Hardware list for cafe network.

Hello,

I'm looking to update my network to something better for my coffee shop. I offer free wifi to my customers, peak customers would be 30. I want two separate networks, one for point of sale, and one for guests. I'd like to have a captive portal, to at least get them on either my FB page, or website page, even if it's just a second. The shop is 1500 sq ft. with outside seating. I was thinking of going with Unifi, with the following hardware:

Ubiquiti UniFi Switch 8 60W

Ubiquiti Networks UAP-AC-Pro-E

Ubiquiti Unifi Security Gateway

Ubiquiti Unifi Cloud Key

Is that everything I need, is it over kill? Should I be looking at anything else? Thanks for your help.