[magman]

I personally wound not get a Feigao motor period. Don't skip on your power system! If you do, you will end up spending much more in the end as opposed to buying it right once. For a 6s set up, go w/a Tekin TT2345 1400kv buggy motor. Much better choice.

As far as which pinions and gearing...this is your best friend...http://www.scriptasylum.com/rc_speed/index.html

RCM has plenty of 5mm bore pinions to choose from in the store as well as the Tekin motor I listed above

As far as wheel tire combos...1/8 buggy wheels- badland tires for all around bashing are superb. ( They are not so good on a track ) Knockoffs to the badlands can be had pre-mounted cheaply on e-bay. I have a knock off set and the work flawlessly