Experience prefold users

I've read good things about green mountain diapers but I am kind of on the fence about them because of there being so many sizes you have to buy. I've also looked into osocozy brand and like those because they only have two sizes. Does anyone have experience with both brands and can tell me which one is the better investment? Also what inexpensive PUL cover is the best? Will I need to buy a few newborn covers instead of one size?