Well, you can have either, but I would lean toward cyborg.
Let's analyze this and break it down a bit. This is how my mind works, so humor me, I lean on a very Euclidean way of thinking (with a bit of dyslexia for good measure). It's what makes me such a good programmer. We'll start by defining what these things are.
- Android - a humanoid robot. But it's much more than that because we have robots and we have robots in humanoid form. So I will define it as a robot controlled by an advanced AI, something that approaches the level of a human mind. Rather or not it has to be sentient (self aware) is a matter for scholarly debate. It also has to take humanoid form. You could have an extremely smart self aware car, like KITT (Knight Industries Two Thousand, from Nightrider) but you would not call it an android, the same applies to drones or aircraft with a high level AI built in.
- Cyborg - a robotic human. Simply we could say this is the opposite of an android. But it has to be more then that, and it has to be more then humans with mechanical parts, because we already have that. So I will define it as humans consciously controlling robotic parts that are an intimate part of themselves. Like an arm, but not like a pacemaker. Also it is not a human controlling a robot by remote control. We have that too and have had that for sometime, we don't quite have a machine human (brain) interface, but we are close.
A lot of people make the mistake of not defining specifically what they are talking about, I'm not one of them. Perhaps you definition of these things are different then mine. But this is my post, so I will use my definition of them.
So lets outline some of the similarities. They both use mechanical parts that resemble human parts. Now rather or not they are covered in organic skin is not really important to my discussion here.. In other words a metal arm is not fundamentally different then a metal arm covered in skin. Granted there could be some major differences depending on how real you want to make it, does it bleed. is the skin warm, is it mechanically quiet etc. But, the fundamental nature of the "robotic" part could be said to work the same for either an android or a cyborg. You could have an android that has humanoid form that doesn't mimic a human. And you could have a cyborg that has humanoid form but doesn't mimic a human (as described above). So you could have a cyborg that from the outside looks the exact same as an android. On the surface is A=B and B=C, then A=C.
Let's look at the main differences. The simple answer is who is controlling the robotics. A robotic arm is a robotic arm. One controlled by AI would be said to be android, one controlled by an organic human mind would said to be cyborg.
Now these 2 control systems can have very different technologies involved. For a cyborg, it more about the brain machine interface. For an android its more about artificial intelligence. The two things diverge at this point, this is the defining difference. As I said, you could have a robotic body that could be interchangeable between a human brain, and an AI core. This is the main item that separates and defines them.
Now that that is out of the way, I would lean towards cyborg being first. Lets look at the reasons I think this.
It's opinion that it would be easier to build a brain machine interface then to build the brain. It's also hard for us humans to give machines the authority to kill humans. We have problems with this right now with drones, and I doubt we would feel any better with more advanced AI given this authority.
There is also a question of why and it brings to mind a third option you didn't mention. I'll cut to the chase and say what it is. That is genetic engineering, and I mean this on an extreme level(humor me).
Ok, back to the why.
I don't think you can justify building androids solely for war not unless you have a very long time of warfare. Certainly they would could be used in warfare, but I don't think they would be developed for warfare (not as I defined them). It makes no sense from a cost standpoint. You could build a AI drone, or tank. It makes no sense from a giving away your technology standpoint. Enemies will capture some of these at some point. And it makes no sense from a morality standpoint.
The main reason I see developing any of this (humanistic technology) is for medical reasons. People are greedy and selfish, and any way to prolong life, or to increase the quality of ones life are things that one could reasonably expect most people to pursue. If you had an arm severed in an accident, or say even military action. Who wouldn't want to regain the use of an arm? I think most people would. So for that we come full circle with the third option. You can build a new arm, or you can grow one.
Now lets look at the why of an android. I am sure there are reasons, but when compared to the above motivation I find myself searching for one that comes even remotely close to that. Something like a glorified butler just doesn't cut it, nor does building a humanoid to do a job a human wouldn't want to do. Sure you could build one for work people cant do, like going into a nuclear reactor. But than again, you could build some kind of tracked vehicle.
Humanoid robots are hard to build, they are much more complex then a simpler design. Often times the form of human is not a requirement for a robot. It could help to be humanoid, to have arms, but does it have to be. All that extra work to make it humanoid could be directed at making it do it's job better. I think people will always pursue building things like androids, for curiosity sake if nothing else. Besides androids are cool.
Even if you argue some rapid advancement in AI that outpaces a human machine interface. You can still have a useful AI in a box. Having an android body is not a requirement of a useful AI. Having a AI is a requirement of an android. Therefor we could have a useful AI and we could have robotics sophisticated enough for an android body, but putting those 2 things in the same entity are not a requirement of either.
One last thing, we could get to the point in genetics where creating a cyborg doesn't make sense at all. If we could engineer living organism and tissues to fulfill any need one may have of mechanical systems then it could skew the motivations. This was the reason I brought up the third option, because the most important question is why. The how is assumed, because if there was no how we wouldn't be talking about this.
Hope my reasoning makes sense, its a bit rambling. I find it best to always go back to the basic questions of: who, what, where, when, how, and why.
