My thoughts are that lego NXT kits might work better. Legos snap together very quickly and the NXT software cdrom has construction plans for a quick robot with a touch and ultrasound sensor. The mindstorms software is a visual application using NI LabView so you don't have to mess around with declaring variable and if statements ...
You can get kits from the
Lego educational division for $250 that include the NiCad battery pack and ac adapter. The technical sales rep. for the Texas area is Betty Justus.