Richard,
Yeah, the most difficult bit is getting the camping gear plus the fishing gear across there. I managed to squeeze everything including tent and an empty backpack into a huge duffel on the way over - on the way back I checked the - now full - backpack separately. American airlines seem pretty relaxed when it comes to amounts of luggage and I flew in and out of Jackson Hole where it was only a short stagger from the carousel to the car rental desk.
Regarding the back country camping, I'd be lying if I said I wasn't a little bit concerned beforehand (especially as I was reading Doug Peacock's Grizzly Years at the time) but you the nice NPS people do get you to watch a video emphasizing the importance of good housekeeping when applying for your permit at the ranger station. I hadn't realised that I'd get the allocated campsite to myself when booking up and I think that was the thing that concerned me most before setting out but, on reflection, that was what made it such a memorable experience. Regarding bear spray, I was lucky in that the flyshop that sold me the spray bought the unused canister back before I returned home (I think both the airlines and UK customs would have something to say about a can of extra-strong mace being carried on!) I did meet a female black bear plus two cubs face to face as I walked around a corner on the trail on the hike back to civilisation. To my shame, after slowly back-pedalling, I reached not for the bear spray but for my camera. Perhaps I would have acted differently had it have been a grizzly!
The fishing? It was very good but the surroundings made it special. As I remember (it was a good few years ago that I was there) the most entertaining tactic was to bounce a Chernobyl Ant off the far bank and wait for the daft cutthroats to respond.
BTW The only grizzly I encountered on that trip was outside the park on the Nth Fork Highway heading down to Cody. Picture below of the young male crashing through the roadside brush.