Gold plugs/pinions

Which gold plugs do it get for a 8xl/9920 setup? The "High Amp. Gold plug 5.5 mm, 150 Amp" or the "3.5mm Gold plugs"?? Is one type better than the other?

Im going to be using 16 ib3800 cells if that makes any difference.

And what type of pinion should i get? im using a 64 tooth traxxas spur and stock slipper for now. Should i get Mod1? what size bore should i get? How many teeth should i get? I want it to reach around 45-50 in second gear.

Thanks for the help