Please help with G3R build

[Zyoss32]

I am building for the first time and have my g3r together except for the tranny and drivetrain, I want to use a center diff and mike's center motor mount but I need the specifics to know what to buy and not waste money. Can someone please walk me through exactly what to buy brand model # for the parts i will need to finish this project, I have 3 motor options tekin 1700kv, 1515 neu 3d,
1521 neu can use any of these what changes do i need to do for the drive train also do i half to have special made or can i buy one to work with one of these motors. if need special made what length and who can do this for me, I know alot of you have done this build and have that info so i can copy.thanks so much i need a lot of advice i know.

Clayce