Re: just one diaper
I would probably go for BG 4.0 with aplix. Easiest for eveyone to use, and we don't get leaks as long as we use the newborn insert. If I were the only one doing the diapering, I might go with cotton prefolds, snappis, and Blueberry Coveralls in Aplix. Only reason I say "might" is because now that she's mobile, a 1-step diaper is easiest to get on her.
Emily, mom to Clara born 2/8/11 and Nolan born 6/18/13