Starting with the UCAs, you should be golden if you get this style:
Its this style that is known for having some amount of issues with fitment on different trucks:
You won't have a major issue fixing it, most aftermarket brands of wheels will fit, and [for the F150s, to include the Raptor] sometimes a shim as small as an 8th of inch will completely de-conflict it
GFC is really neat and if I was clean slate building my truck again I would probably have looked into that from the get go, but I'm pretty far deep into using the Leitner designs rack. Really the only thing I've not fully be satisfied with has been a roof top tent, and of course now I'm looking at clamshells (iKamper clamshell in particular) and thats what GFC does... That being said if you go with a GFC topper I would PRIORITIZE leafs. Its not nearly as dire of an issue in a F150 vice Raptor, but you still got a block and you still could might sag. I don't think you'd sag after adding a GFC alone as they're about 300 pounds, its once you add your gear to the bed and passengers in the truck or when you might have issues. Plus I loathe axle wrap.
To your point, I find myself enjoying the desert a ton but don't necessarily need to be bombing down two tracks and all that. That stuff is treacherous especially with the rains over the past few weeks, lots of roads have turned into nothing thanks to washes. I also don't really want to roll my daily driver or something like that, so much slower scenic routes are on the table for right now. Though I have a project in mind to fix it, just need to know whether I will be staying on the west coast before I get started.