Being a bigger guy(I'm 6'2 240) definitely do some research in wheels. There is a whole segment of the wheel market that is almost off-limits to us. Being that your just getting into it, I'd reccommend doing a quality budget build or buying used. You could be anywhere in the 59/60 cm to 63+cm(I know there are many other measurements to think about, just giving barebones) range depending on your build. I always reccommend that people go single speed before going geared or fixed. Riding fixed without knowledge is dangerous, riding geared without a base of knowledge derived from practice is a waste.