Savox is going to be your only choice for less expensive on lipo's, and the better savox HV servos are not available in the states yet. Hitec and KO are what I see alot of people running but for the HV (hitec 7940, 7950 & KO rsX seriers) they are around $130 or more each.

Edit: I didn't think about the 7955, it is priced lower than the others.