We aren't using cloth at the moment (I can't even keep up with my clothes laundry due to a sucky laundry situation), but with our older DS we used exclusively cloth until 14 months, when I couldn't handle the laundry due to morning sickness. I really think prefolds are the absolute best until they start to get mobile, at which point I wanted something trimmer because my super chubby little guy was having trouble with the bulk of his prefolds. I actually used exclusively flats for probably 9 months.
Anyway that doesn't really answer your questions. I personally would not get many newborn diapers. Even when they're born little (and I had preemies) they won't be in newborn size for very long at all (I just moved my guys to size 3 disposables, if that tells you anything). Smalls really have a longer life. One of the benefits of prefolds is they fit a large size range. And I was able to make small Bummis Super Whisper Wrap covers fit for a loooong time, over both infant and premium PFs (if I recall correctly).
If I were doing cloth I'd want about 35 infant prefolds and 6-8 covers. If you do want smaller ones, I really recommend the orange-edged prefolds from Green Mountain Diapers. Those are a non-standard size, good for little babes. You will go through a LOT of diapers at first. Just expect to be doing laundry almost constantly (especially if you also have spitters
) In addition to those, I'd probably want a dozen Kissaluv 0s or other fitteds (the KL0s are not too expensive and worked great for us) to use at night for easy changes.
Oh yeah, one other thing: we had an eco-friendly diaper service for a while when DS1 was little, and I highly recommend that route. I would definitely do cloth if there was a local diaper service. Also, I always got a better fit pinning than with Snappis, but get some of each to see which you prefer