For backpack, I am decided on the Baltoro, but unsure of the 75L version...is that an overkill compared to the 65 for a trip of this duration?
The optimal pack size depends on trip duration AND type of gear you plan to bring. I can easily do a 100+ mile lap in the mountains w/o resupplies with a 30L pack containing all essential items, but my gear is very light (and I normally leave the grill and a flat screen TV at home :))
If you are looking for a new pack, consider investing in a modern Cuben fiber design instead of a 5lb+ monster from a mainstream company. You will pay more, but the benefits are substantial. These packs last much longer and they are much lighter.
Check out https://www.hyperlitemountaingear.com
- they currently have a sale.
If you do a simple math, the difference in weight equals a bear canister and an extra day of food, not to mention that people with large packs often tend to bring useless items that only slow them down. Would you rather carry 25-30 lbs over multiple passes (a perfectly reasonable weight for your trip, which does not force you to sacrifice comfort and functionality) or 45-50 lbs?