Hello...
Yes plug an AP into each switch, set the SSID and password to match what you currently have and it should be all done...
Choice of AP is entirely personal, and my personal choice is to avoid Ubiquity, which I am sure has come up. And of course budget is often a deciding factor.
I find TP link to be acceptable most of the time, and I try to avoid home systems that have a "controller" like Netgears Orbi. I have no experience of TP Link Deco unfortunately.
With regards to speed, wifi 6/6e and 7 speeds are theroetical. Most switches have 1Gb ports so that's the maximum speed possible. Most phones have just a single antenna so can NEVER get the full speed from wifi 6/6e and 7 because the speeds are predicated on both AP AND host device having multiple antennas so the data-streams can be multiplexed. I could talk about this for a long time. Most phones will see about 500Mb/s depending on all sorts of boring things that the adverts never mention...
Oh yeah, forgot to add... 99% of wifi problems I see are not network related, they are user device and user-not-understanding-how-wifi-really-works related...