I've been blessed with a room-full of DIY rams (dall and others), I'm sure others have too, but here are my thoughts after years of trial and error...

Take the hiking sticks. I question the sanity of anyone who doesn't use them. Use anti-shock. Between my friends and I several of us experience instant wrist problems if we don't use the anti-shock spring-loaded style.

Do NOT take moth balls into the pristine wilds. That poison has no business on a sheep hunt! A few drops of pine sol may work fine to deter bears, I dunno.

Try your friends backpack out. Wear it with weight, train with it.
Take it to a reputable outdoor shop, if they fit it to you and it feels great, use it. Save the $600 guys are giving way for a Kifaru. If it won't work, bite the bullet or ask your guide for his take. He might have one.

Take the fly rod. If your guide says leave it behind with your flying (travel) clothes, leave it behind. Better to be prepared for some great grayling fishing than wish you had it.
I lived in AK and have had my chance to catch the helloutta them, so I wouldn't bring it myself. If you've never caught them? Bring it and hope for an opportunity.

Don't use an antiperspirant anything. That seems like a no-brainer to anyone who is health minded, but clogging your armpit pores, feet etc. is stupidity, imho.
You sweat for a reason. Wear good socks to wick moisture.
For your pits, buy a scent-free all-natural deodorant like Tom's of Maine and cut the deo stick out of it and put it in a zip lock. Use as needed. Gold bond has a strong odor, I'd leave that [bleep] at home.

Take the .308 and the Leupy. If, like you said, you have a good bear load for it, use that gun for both species with confidence.

Check with your guide; he'll very likely have a rangefinder, if not, take one. I missed my first ram without one years ago and swore I'd never sheep or goat hunt without one again. It's been 100% success since.

Leave the gaiters off the sheep mountain. They are just more weight and constriction and aren't necessary. I never use them either way, but I guess for bear country they'd be justified.
Break your boots in well. Train with them.
Don't forget the second skin, or moleskin, for rare blisters or rub spots. If your feet heat up, take the time to air them out properly.

Hope this helps. This advice has come from years of both mistakes and success--all DIY.