Let's Make Robots!

Advice on second robot

I built my first robot out of an Atmel168, cardboard, and some spare parts, last week. Now I'm planning my second one.

What I want build is a robot with wheels, remote control via 802.11, a webcam, and an arm/scoop to pick things up. I've been programming in C++ for several years, but I could use some advice on what hardware to buy.

I'm thinking of getting a Beagleboard or Gumstix Overo for a linux environment (other suggestions welcome)

I'm not sure what to get for a chassis and motor controller though. I built the motor control circuit for my first robot, and made the chassis from cardboard lol. Can anyone suggest a good chassis? I'm thinking something in the Roomba size range.