Since you’re both newish to fly fishing, the #1 thing that will make the trip more enjoyable is getting your setups as soon as possible and practice casting. I’ve known newbies with $1k setups that pack into a world class set of lakes without practicing, get frustrated with basic casting and quit the first day.
You don’t even need water - use the ugliest fly that someone gave you, or you found hooked to a tree and cut the entire hook off so it won’t snag on anything. I teach kids by putting out a paper plate on a big lawn or park and casting to it. If there’s a breeze, practice casting with the wind at first, but then cross wind and finally into the wind, which only works with slight breezes.
For high lakes it’s better to be able to cast accurately to different rocks on the shore than it is long distances, but distance will improve with practice. Still, brush and trees will be the enemy and you’ll be forced to look over your shoulder to see how to avoid them as you cast. It’s important to get the timing and movement down so you’re not making wind knots in the leader, snapping off flies, or constantly getting tangled up.
If you can’t figure out how to cast, have a friend show you, or go to a fly shop and pay for an hour of time for them to show you what’s going wrong.
One weekend my nephew asked me to line him out and show him how to cast - every night he’d practice on the lawn, I stopped in after a few days to help with the problems he couldn’t figure out, and the next weekend he caught a bigger cutthroat than I ever have on his first day of fishing. Lol
When you’re starting out don’t skimp on leaders - pack at least 4 for each of you and you’ll still come back with short fat stubs. By the best line you can afford, and a line cleaner and conditioner. Reel doesn’t matter.
If you live in a windy state, you’ll eventually gravitate to a moderate/fast or fast action - but to start with it probably doesn’t matter. As others have said, a 4 piece, 5 wt, 9’ is the go-to size for most western fishing. Weight forward floating line designed for trout is easy to find - avoid cheap line like the plague.
I like the flies mentioned above - especially elk hair cadis. Don’t forget fly floatant.
Have fun - sounds like a great time!