Re: Sizing prefolds
We did the traditional size infant prefold. It was super bulky. When I lay baby down his back was arched. I regretted not getting the new shorter size prefolds. Whichever brand you choose to go with I would pick the newer sizes. You can still pin or snappi them but you can also trifold as you mentioned. I have never done the trifolding but have read other mamas saying what you mentioned. It makes for a very messy cover weather EBF or formula fed.
Baby isn't likely to fit long in the nb sizes but since you are going Pockets which I am assuming are OS(ignore this if you chose sized) this won't be an issue. The nb typically fit to about 10lbs. Your pockets should begin to start fitting at around 10lbs. Anyway that is what most mamas on here say about the OS pockets. FYI I use wool so don't have first hand knowledge just what others have said previously.
Oh yeah welcome to DS. All daddys are welcome most are just not usually interested enough to join.