What NGFW actually works for a 300-user retail chain with PCI compliance?

Hi everyone. I'm setting up security for a retail chain with about 300 users across 20 locations. We handle credit card transactions, so PCI DSS compliance is a must.

We're looking at Palo Alto NGFWs, but I'm a bit lost on which model would actually fit. I see PA-400, PA-1400 series, and VM-Series. Our main needs are:
* Segmenting the POS network from the rest
* Good threat prevention for cardholder data environment
* Central management for all stores would be a huge plus

Has anyone deployed Palo Alto in a similar retail/PCI setup? What was your experience? Any specific gotchas or models you'd recommend for this scale? I'm worried about picking something too weak or way overkill.

Learning the ropes.