Timbo said:
You seem to be very concerned with wheelies. Start off with 16/49 and watch how quickly wheelies become annoying. You should also invest in an aluminum rear diff cup and rear rims with a reinforced hex hub area. Take a look at this chart:
http://www.hpiracing.com/graphics/instr/savagegears.jpg
Higher numbers = steeper gear = more wheelies = less top speed.