Plett Powered Hyper 7 TQ Sport Project

Well, I received my BigMAXXimum (along with a ton of other parts:D ) and started the design of the custom motor mount. I'm using a center slipper clutch spur from an Ofna Dominator, so that I can use a plastic spur gear and have some geartrain protection. I'm going to use the 65T Mod 1 Spur Gear and would like to know what size pinion gear to use? I want a balance between low and top speed, and want to keep the temp of the motor and speed control to a minimum.

Also, I would like to know what Polyquest LiPoly to use with the Schulze 18.97 and the Pletty? Should I use a 4S or 5S and what capacity? By using LiPolys, am I running a risk of damaging the speed control because of the amount of current that the LiPolys can deliver? Comments and suggestions are welcome! :)