There is the Sentinel that is a Portal Builder android that could serve as inspiration. But the most important is to determine which culture would have first developped robot technology. I think the Order of the Pariah and maybe the Draconites would be plausible candidates for that.
In the supplement on artifacts, you have a few suggestions of Faction tech. The Order of the Pariah has automated combat exos I think, not sure though. I would need to check that out.
Mechanics wise, I might offer the player to be more specialized as a robot, depending on the model it would in a specific field. Starting characters can't spend more than 3 on their main skills, I might offer the possibility of spending a 4 on main skills, but make certain skills unbuyable, ever. Or capped at a three maximum?
But the main thing I would do is list which cybernetics could be bought and paid in XP for, and maybe extend that list.
The main difference with a human PC will be roleplay, and the fact that no upgrade of skills or talents can occur without also spending birr and going to the "garage".