I really wouldn't recommend the U7-Pro yet. The Unifi Community forums are full of complaints about stabilty, software issues, and they have internal fans to deal with heat.
The U6 Pro is very stable by comparison and surprisingly capable for the price. If you want to go 6GHz, the U6-Enterprise is a pretty good choice.
Just remember the Unifi auto-channel selection algorithm isn't great and most APs end up sitting in UNII1 - (36 - 44) in the 5GHz band so you may want to look at manual channel planning.
