RE: what needs to be changed on this to be lipo
The answer: Nothing!
A 2S LiPoly is about the same as a 7-cell NiCd or NiMH. You'll want a pack capable of about 40 Amps of load, which is going to mean at least two packs in parallel for most LiPoly technology out there. A 2S2P Thunder Power 2100, and 2S2P Kokam 2000 (15C) are two choices.