Enerland celled packs(Neu, Flight Power, Poly Quest) packs, Neu motors(1515 for Truggy/ 1512 for Buggy), and a MMM(once a comepletely succesful batch is released) will solve the failure and heat issues. 5000mah will get you a solid 15 min.s in a buggy and 12 or so min.s in a Truggy at near expert pace.

If you want to run 12/46 you'll probably want the 1512/2d @ 2550kv. I think the 2.5d(2050kv) with a 14 or even possibly 15 would be a better choice, though.

Someone else will probaby chime in. I've found lower kv/higher gear combos lead to happpier compenents.