need help gearing my brushless emaxx.

[blueb8llz]

i know its best to buy a few sets up pinion/spurs and try it myself but i really dont want to spend money on that sorta stuff just yet so which is why im asking you guys that have the experience already.
i have a 3905 and will be running a mmm, feigao 7xl, trakpower or neu energy 5000 20c. i really wont be doing too much speed runs, mainly bashing. my questin is whats the tallest pinion i can put onto a stock 68t spur to reach the fastest speed, yet not too big so i have to worry about thermal on the motor.
and with this pinion, will i still be able to wheelie on command even though its geared for more topend? i want something in the low 40's. i was gonna gear it 24/68 but someone told me i would only be getting 35mph with that. i can move up to a 26-28 but im not sure itll fit plus i dont want thermal or am i good to go with that size. or will i HAVE to switch out my spur to get the best setup? main thing is, i want the fastest setup without losing th abiltiy to wheelie and not have to worry bout thermalling. just a reminder, i dont do many speed runs so i think that will keep the motor a lit bit cooler than most of how you guys run your trucks.
thanks for the help guys and sorry for the long post. its just because i am going to place my order (not the mmm) first thing tomo and i want to get all the info i can get now, and so that i dont have to do the trial and error thing and end up wasting money on exttra pinions and spurs. yea im a cheapo when it comes to those two things cus i noticed once i have a set spur/pinion, i NEVER change it for some reason...well thats when i had my buggies and stadium trucks and onroad cars.