I'd say the Mamba Monster is still king really as far as esc options go- there are a couple different versions, not sure of the real difference but either will work fine. If you want a cheaper option then look at the hobbywing and hobby king offerings. As for batteries, there are tons of new flavours from hobbyking, as well as all the old favourites- prices are a lot better and reliability also, so look around. I think most of the links I gathered up years back are still valid:
http://www.robotwars.00server.com/usefullinks.html
Probably...