Yeah I don't recall all of the different options either, my SUT is an 05 LUX and is now over 10 years old and the only option I did not have was the air ride in the rear and rear seat DVD players. Everything else was included. As far as upgrades. My upgrades in order were:
1. Ditched factory chrome nerf bars for U-steps and added Gobi rooftop and SUT racks also added Ram Safari Brush Guard.
2. 37" M/T tires and torsion bar leveling
3. Exhaust and airdoc/AFE cold air intake also added rancho adjustable shocks
4. Front locker and 4.56 gears but I should have gone to 4.88s
5. Dmax Kryptonite Steering upgrade kit, including centerlink, tie-rods, pitman/idler support kit, etc..
6. Winch and cradle for front receiver hitch
7. On board air compressor
8. Modified the rock rails to bump them out an extra 1.5"
9. Long tube headers and custom tune
For me the SUT was very capable right out of the gate, even with all terrain tires and the upgrade to 37" MTs made an even bigger difference because I could air them down and get great traction on just about everything, but thats when the trouble started with the front end and the steering. Just the torque on the front end would bend the flimsy OEM tie-rods like twigs and once the tie-rods went, the front cv half shafts were next and would just grenade themselves. So the upgrade to bigger beefier tie-rods and centerlink was a must for me, but you could probably get by with just the HD tie-rods, I only chose to do everything because my pitman/idler was worn out and since I was pulling everything anyway it just made since to go ahead and been everything up while I had it apart. The gears and front locker were next, the locker was not a necessity, but while the diff was open again it just made since to put it in. The locker helped me tremendously because I had a hard time with allowing the traction control to do its thing and I would constantly override it by pressing the brake using BTM and the front locker was like pushing the easy button at staples. It would basically crawl up and over anything I could throw at it, well at least to the point of high centering the truck. Since its not lifted, high centering it is the biggest issue, but the trick is to have good spotters so you can get good wheel placement and as long as you can find a little bit of traction, you will be amazed at how much the H2 can crawl.
As far as the practical mileage you might expect to see, the type of driving is the biggest difference. I am about 70-80% highway and I average between 12.5 and 13.0, but thats with the mods listed above. Before the mods, I was up around 14 mpg with my 70-80% highway driving. On the trail you can expect to be in the 8 range if I recall, but its been years since I even bothered to check that, because its smiles per gallon that count and not miles per gallon.
Like I said my SUT is currently over 10 years old and has just over 195,000 miles and I suspect as long as you keep up your maintenance, you can get well over 250k out of the motor, but I have had friends who had to deal with motor replacement right around the 190k to 200k mark. I have never once regretted my SUT and I still enjoy driving the truck everyday, so I plan on keeping it for quite sometime.
