Thanks for the reply; I'm happy to use Michael's cloud controller if he's ok with that, and the help available here on GZ is ever-useful when things get confusing.
Yeah, it would make sense with going with the new models, provided it's not an enormous price premium (as it'll come at the cost of delaying a new receiver!). It's only a 140m2 house, but with the external HT/sleepout at the back it's a fairly long coverage area relative to its width. The image below shows the placement of the APs (yellow dots). Do you think 2x U6-Lites will provide adequate coverage?
One Unifi AP-LR (older N model) in my parents lounge covers their entire 360m2 house. I'm sure two would easily do 140m2.