Typically, you'd be getting a push from a deadstop, so cogging wouldn't be an issue from a dead stop.
The micro motors and speedos do indeed fit! Word of caution, DO NOT buy super big 9000kv BL motors for the bikes. Usable powerband is very important to control them, and those big motors are a handfull (ie: not fun).
Check out hobbyetc.com for an extensive list of goodies for Kyosho's 1/8 motorcycle.