Congrats on your pregnancy!
Fit and absorbancy wise (at least initially) and for a good all rounder I think you'd be best going for the Pop-ins. Ittis are very much a love or hate nappy, and many people find they have periods of them not fitting baby well - plus they are sized so would be more expensive having to buy the next size up as baby grows.
You need to bear in mind that not all nappies suit all babies, so I think buying a birth-potty pack of one type of nappy could potentially be an expensive mistake. You will probably be better off buying one or 2 nappies at a time and getting a feel of what works best for you. Buying gradually and experimenting is the most cost effective and fun way to do it in my experience!
Incidently, my first nappies were 12 preloved Pop-ins, which were fine for the first few weeks as I bought others to try out - but after a while we didnt get on with the fit and started to get a few leaks. I also said from the start I'd only use AIOs/pockets as they are easiest - however my nappy collection now mostly consists of fitteds, which we use under wool!