ZIPZAP MOTORS:
10,000 RPM HAndling Motor slowest but has a lot! of torque...
16,000 RPM Performance a little faster but a little less torque
21,500 RPM Turbo my favorite motor perfect blend of speed and toruqe..
23,500 RPM NOS motor a very good choice for drag racing but its low torque makes not that good on tracks this is the fastest ZIPZAP motor.
Bit Char-G
16.000 RPM slowest motor that can be bought normal...like zipzaps 10.000 it is the torquiest motor but a little slow top-end
26.000 RPM the best bit motor in my opinion a nice blend of speed and torque
30.000 RPM gettin really fast with this motor can still be used on trcks bu is best at draging
32.000 RPM really really fast this motor is mainly for dragging of course the toruq has droped alot!!!
38.000 RPM the fastest that can bought better not try and turn unless you like makin flips...
as for the speed with dual cell mod it is basically the same except your gonna go alot faster with anyone of the motors!!
DKS motors I do not have any experience with but here is a link:
DKS
But the motor isnt everything the gearing matters alot as well but you prolly know about that!!!