help with gearing

[Tosch]

I'm planning a brushless truggy for bashing + some track driving in the future also. This is the setup i'm thinking now.

Mugen MBX6T, RCMonster mbx6t brushless cobversion kit, Tekin 1700Kv or 1550kv truggy combo with a 5s 5000mah G3 Hyperion battery pack.

I'm looking for a reliable package.

Do you think this is a good setup? What pinion size should i get?