The solid works files are included for the 2 parts and also a DXF ready to cut with a laser cutter.
The robot was designed to be held together with blue tack or tape.
I have personally built the shrimpy with Wheels - http://goo.gl/f8DB8 Motor controller - http://goo.gl/dbDhg Ultrasonic distance sensor - http://goo.gl/g498G Motors - http://goo.gl/BQQdJ UBEC - http://goo.gl/Dg9CF The UBEC with a little soldering and the end of a micro USB cable to allow you to power the pi from 6 AA batteries.
Those are just some ideas for items, you are likely to find them cheaper ones if you shop around.
I have included some example python code for object avoidance and some example scratch programs for remote control.
All work is licensed under the GNU General Public License. This can be found in the COPYING file.