For coolers I'd just go to WalMart. There'll be plenty along the way on I-15. I-15 north then west at Park Valley is a much nicer route than going west on I-80 to NV then north to Grouse Creek. As stated above, there's a Sportsman's just off I-15 in Riverdale that'd be easy to get to on the way. As far as eateries heading north, I'd suggest either Jerimiah's in Ogden or Ruby River in Riverdale.
After re-reading the OP, I don't think I'd be buying some of that stuff once I landed. I know I'd want a few nights in and lots of looking over of a sleeping bag, for example, before heading most way across the country. If you can't get everything you need into 2 checked bags and a carry on for the trip to UT I'd say you're packing too much. The $50 savings on the second bag would not be worth having to rely on some new gear that may have problems.
Make sure to stope in at the Grouse Creek Mall...
