flyrods are like guns.....there isn't a universal platform.
the beartooth mnts (if I remember correctly) are mostly wooded so the wind won't be a major concern (versus the little blackfoot....wind knots out the ying yang). with that said you will be fine there with a 4 pc 9' 5wt. the weights only determine the line weight (higher line weight = heavier rod = heavier conditions).
Speaking from personal experience buy the best that you can afford because it will always be cheaper in the long run than to keep buying over and over and end up with a closet full of gear.
My personal favorite is a winston rod and a ross reel. these are tough and sport a lifetime warranty (trust me don't get one without a lifetime warranty....they break faster than you think). you can find good deals on gear via craigslist or ebay and since you are just getting started why does it matter if you have used gear?
do you have breathable waders? even in august that water is not going to be "warm" how about boots? a vest? etc
Once you get your gear I can take you out on the water and let you fish with us sometime to get a feel for things if you like.
I agree on getting the best I can afford, hence me trying to trade my stash to cut some of the potential wife giving me the evil eye. I've never been up there, but looking at youtube vids and from what I've been told, we'll be going from lake to lake during the hike. I used to have a fly rig about 15 years ago, and never actually fished with it, but I did practice casting. I will most certainly take you up on the offer. Trout Slayer made the same offer.