Brushed/brushless Upgrade For Twin Det And E-zilla

[tamiya monkey]

just bought a e-zilla and a twin detonator and was woundering if anyone could advise me on a good setup for these fun trucks, might twin two batteries in the twin det if need be, also can anyone recommend some pinions for the e-zilla wanted some smaller ones 17t or 18t but cant find them anywhere is there some other pinions that would suit that are easier to find or someone that sells them.