I just bought 13 bumgenius aio size small for $90 on this site & I plan on selling them to buy OS once she outgrows them. She's 6 wks now.
I was planning on using prefolds & covers from birth but I couldn't get it figured out to make it successful for us. So before I bought the BG I had some itti bitti snap in one, a happy heiny mini OS, simplex NB, a few wahm. I really like the happy heiny mini OS, but it's a pocket.
From my (limited!) experience so far I would suggest getting a few different brands sized for NB & then go from there. A lot of the different cloth diaper stores online will have specials where if you spend a certain $ then you get a free one size, and they might have a brand on sale too. I got the itti bitti for buy 3 get one free, then the extra diaper for free for spending the money. I also won 2 free thirsties from a raffle copter from Facebook & twitter.