another one for the $50 robot

[ajax spray n wipe]

For my $50 robot, I want to put either a sonar rangefinder or a sharp  IR rangefinder. With either choice, could anyone please tell me if having a maximum range of ~5 metres is too much for a robot that might be used as a sumo bot?
Also for the IR rangfinder, is having 2 rangefinders (1st one:20cm-150cm; 2nd one:100cm-550cm) of different ranges a good idea, or am I doomed to fail?
Could anyone please reccomend an MCU for the ATmega168 chip that has in-built DC motor drivers or H-bridge so that I can use DC motors intead of servos for moving around?
Thanks.

[airman00]

what do you plan to build?


and also why are you building the $50 robot MCU , if you are just going to buy your own?

H bridges come in DIP packages also, so you could add it yourself to the $50 robot mcu