For about 30 years I tended to buy Monroe (mostly) and sometimes Gabriel shocks and have installed quite a few on my vehicles. I was buying on price. They don't seem to last very long for DD use and usually 1 out a set will leak in less than 2 years. On a few I was able to get a replacement no charge, but on one expensive set I wasn't able to (that was NAPA's call and the guy was too lazy to look my order up). But why should I need to do that? Personally, I'd lean towards Bilstein's because overall they have a stellar quality rating. Anyway, I stopped buying Monroe or Gabriel shocks.
I bought a set of OEM GM shocks for my H3 (same part # as OEM) but haven't installed them. GM claims they spent quite a bit of time tuning the suspension on H3's, and there are multiple shock numbers depending on the suspension pkg your vehicle has, that's one reason I wanted to stick to a factory shock. The GM (AC Delco actually) replacements look exactly like the originals right down to the original markings, stampings and plastic boots. The ones I bought match the part number on my vehicle. To be honest, I haven't noticed any ride issues with my vehicle, but I wanted to buy Factory replacements in case GM discontinues them. At 160k I went to install them but after removing and hand-testing 1 rear and 1 front, I couldn't detect any looseness or shock travel issues so put the old ones back on. Maybe next year or the year after I'll replace. GM replacements cost a lot more than the Monroe's but I know they're tuned right and I've NEVER in 35 years had a pair of Monroe's last 50k miles w/o leaking.
Sooo, dollar for dollar, hard to beat Factory shocks for longevity. For comparison sakes, my wife's DD jeep has over 200k on original shocks (still rides nice) and my Tk has 150k on original shocks (rides perfect ..although 1 has started to leak). Land Rover used Bilstien shocks for years and a lot of owners would get 150k or more out of them. A member on the Land Rover forum once took his Bilstiens at high miles and put on a shock tester he had access to (with new bushings) and was surprised they were within specs. If Factory shocks weren't available for the H3 I probably would have went with Bilstiens.
You have the right idea to pay a little more up front for the Bilstiens. I can't comment on Fox shocks.
On Diff bushings, I recently installed an inexpensive $15 stock-looking China bushing I found on ebay. The quality looked as good as any Moogs or Delco I've installed over the years. I'll report how long it lasts. I just did the center. I considered the urethane kit ...I may install them if I have to remove the entire front diff, but I had to plug an emergency bushing so I went cheap on that one. I have a press so removal/install was a breeze, ..even if I have to do it again in 50k miles. If you wheel or drive hard-core, probably should bone up for the better bushings. They look well made.
