I use the GP Master Caddy. I like it because I didn't have to build it. Has a power panel, Super X fuel pump, plenty of room for most tools.
See it here:
http://www2.towerhobbies.com/cgi-bin...1&I=LXPS86&P=7
Also: this one is nice (friend has it):
http://www2.towerhobbies.com/cgi-bin...1&I=LXL417&P=7