My suggestion for going with a newer model was based off the fact that you could probably find one for $2000-4000 in incredible shape if you look around.
I definitely agree that the first gens are easier to work on, and some of the parts for them are dirt cheap now, so from a budget standpoint in terms of DIY maintenance they are hard to beat.
However, since the economy is such that people are selling off their SUVs for just a few grand because that's all they can get, it's a heck of a time if you're wanting to buy.
The benefits of the 4.0 SOHC vs. the OHV are more power and torque, a broader RPM range in terms of torque/power, and bigger gains in terms of mods. Mostly this is due to the OHC design vs. the pushrod OHV design, but there were other changes throughout the years. The SOHC does have it's own issues though, with timing chain noise and chains in the rear of the engine, as well as just being more complex than the OHV.
My suggestion for the SOHC is also based off your wanting of more power, which is easily done by going to a SOHC, which starts off stock with more than the OHV with mods. Add headers, exhaust, ECU tuning, etc. to that and you are going places.
A first gen is a lot of fun, and I wouldn't trade mine for anything. BUT if you don't have a place to work on it or do the stuff it needs, you might consider the cost of keeping it vs. spending a grand or two on a newer model that will hopefully need little if any maintenance, not to mention the savings in time.
Not that we wouldn't love to have you in the first gen forums from here on, but it would be simpler and better to sell off a running vehicle and get another that suits your needs, rather than dig yourself into a project that keeps going and getting more expensive, then having to get rid of it and drop the money on something else to drive later on anyway.
