Narrow down by all means but do be flexible...remember you don't know what build your LO will be and your opinion can change.
Both DH & I are small, 5'4", so I expected a petite baby who would get on great in the little lamb bamboos I invested in.
We now have a big chunky thighed lady who outgrew the size 1s at 4.5 mths & even gets chaffing around the legs in the size 2. Still use them as night nappies but I've 25 that I only got 2 month's use out of, and more than I need of the size 2...just because she's chubby!
Also I'm veeeery slow & meticulous putting nappies on so it takes me ages. Starting to wonder if I shouldn't have bought all in ones instead.
So do try different types before you buy in bulk and if you'd like to try one or two little lambs or tots bots bamboozle stretch feel free to PM me