Help with choosing parts for a first robot, please.

[dotDominic]

Ok, great. Thanks very much!

[dotDominic]

Ok, so I'm thinking about to buy a charger for this battery:
http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html, which I'm using to power 4 12v cordless drill motors.
I've read in several other threads/posts on this forum that the IMAX B6 is a good first charger, but it needs a separate power supply. Considering the vast range in prices of power supplies, I'm very unsure which one to buy. Could anyone give me any advice on which would be a suitable (and relatively cheap) power supply for the IMAX B6, please?