start off with a construction chart of a basic model. insteed of career generation it becomes program generation (assumeing it is self aware it picks up skills normally) the robot would be picked by referee and player and instead of wealth it could increase it self a rough example would be a virises maintenance robot becomes self aware and over time learms programs itself and of course modifys itself. one problem is in virus times a robot is a very dangerous thing to have around. and keep in mind the player for his more powerful character has the constant risk of becoming infected (loseing his cool character) if he say gets outa hand.

Hmm the GM says. The base robot you have rolled up was prior to virus a garbage bot supervisor unit

As for overpowered robotic characters not really a problem since the introduction of the plasma basooker.

Your robot character could bring you a LOT of trouble, imagine landing on an xenophobic world and you and your robot buddy walk down the ramp, how long would it be before you were running up that ramp with a lynch mob in hot pursuit?  A cyborg might be a better way to go (I picture the movie West World), build a robot to human size, cover it with human-like skin.  Programing it could be the biggest glitch, even the best robot brain only allows a handful of skills to be programed into the robot.  To get around this we just state that when a robot becomes self-aware it gains and improves skills like a human.  Below is a robot from a previous campaign.
   ROBODINE'S CHAMBERS CYBORG
TL-15                                Tr Move:20/20
Price: MCr 2.1                   Com Move: 2/ 10/ 20/ 30
Mass: 60  kg                     Fuej Cap: 1.2 ltrs
Power: 0.004mw PNF         Fuel Cons: 0.008 ltrs/ hour
Maint: 1/ 100 weeks          Armor Value: Head: 2
                          Attributes
STR: 2D6    AGL: 2D6    CON: 2D6     INT: 5+D6
EDU: INT +D6/2     SOC: 2D6-2
                     Basic Programing
Carousing: 2   Computer: 2   Liaison: 2    Observation: 2    
Service: 2   Streetwise: 2            
                  Advanced Programing
Basic programing is barely enough to allow the cyborg to function in society so Robodine offers an additional programing package equivalent to first term skills in any field plus 5 additional skills.  Cost: Cr 24,000
                 Far Trader Companion
Electronics 1, Ev Suit 1, Gravitics 1, Liaison 1, Mechanic 1,
Pilot(Interface/ Grav) 1, Cargo Handling 1, Security 1, Service 1, Ship's Engineering 1, Zero-G 1.

Finally we added this stipulation:  Due to their unique computer brains cyborgs are virus-proof and are self aware and capable of learning as any other human.