I think it would be easier if you stick to one of your threads instead of spreading your issues across multiple threads.
Lots of ways to skin this cat, but the easiest for a DIY person is to get a Dream Machine for those AP's. If you want to mix and match and keep costs down then generally the exchange is greater complexity and care. Saving a few bucks makes sense when you don't have the bucks. Spending the money makes sense when you take a look at the time you will need to spend and check that against how you would value your time.
All that said, if you have a remote dealer or someone that helps you with stuff and you intend to use them in the future, you may want to take their advice on what they are comfortable working with. Unifi is really easy if you are all Unifi and giving remote access to the network when needed is a couple clicks.