I'll give it a shot.
You can get the
TeknoRC convesion kit $145
The
Castle creations MMM ESC $145 (if it breaks, Castle will replace it)
RCM pinion 13t $12
Medusa Motor
MR-036-060-2000V2-5 $115
ZIPPY-R 4800mAh 25C 6S1P Lipo $118
Use
THIS charger $57
and
THIS power supply $18
Using a 13t pinion and a 40t spur you should get the speeds you want;
Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.8333333333333332
Other Ratio: 1
Spur Tooth Count: 40
Pinion Tooth Count: 13
Total Voltage: 22.2
Motor KV: 2000
Tire Diameter (inches): 5.9
Tire Ballooning (inches): 0
Motor Current Draw: 110
Motor coil Ω: 0.006
Spur/Pinion Ratio: 3.08 : 1
Total Ratio: 16.05523 : 1
Tire Circumference (inches): 18.54 inches (470.8 mm)
Total Motor Speed: 43080 RPM
Vehicle Speed: 47.1 mph (75.65 km/h)
Estimated Adjusted Speed: 44 mph (71 km/h) - 6% loss
Effective KV Value: 1940.54
KT constant: 0.68 oz-in/A
Motor Torque: 0.39 ft-lbs
Final Torque: 6.22 ft-lbs
Final Power: 2442 watts (3.3 HP)
I kept the gearing kinda low because those motors are a bit smaller side for the application. But have a better rep than Feigao. I'm using the "Novak Method" to compensate for motor size. (Use a higher kv motor geared low.)
That gets you to $610 before shipping.