No, doing the vcg's on this should not be bad. Yours is, pretty much, like my '98 AFAIK. One trick is to loosen the brake booster to get at the bolts in the back on that driver's side bank.
As to whether the '94 trooper is "undesirable" - ha, ha, you've come to the wrong place and misunderstood the machine. IMO the whole gamut of 90's troopers is about tops among Japanese SUVs second only to the 98+ 100 Series Toyota Land cruisers. I would not be caught dead in a 4Runner, and I kid you not (and I am a BIG Toyota/Lexus fan). Only '90s era Japanese SUV I would trade my truck for is a 98+ Land Cruiser. And offhand I can't think of an American, English or any other SUV I'd trade it for wrt reliability, design, ease of service, etc. While they fetch more money (now), even an 80 Series Land cruiser is a step down to me (and I've spent miles - lots of miles - in all of the above).
If your VERY first mechanical adventure is to do valve cover gaskets, I suggest no. It takes some feel for materials, metals, some touch and a little skill. If you have a lot of that from say, being a machinist, denstist, maybe an acrobat, then OK.
But I don't want to talk anyone down or away from getting into the very Zen and wonderful hobby of auto maintenance/mechanics/restoration. If you do decide to go into it:
Here are some tips:
a) When you do change the vcgs, go back and re-torque the bolts after running it hot and letting it sit. This will really keep leaks from coming back prematurely. Use some gasket dressing (I use Permatex Aviation #3, there are others) in corners and as a tack to keep it in place.
b) Yes get a kit w/the spark tube seals and change them. Go slow, heat the tabs if needed. It is easy to break them. This takes a little while but needs to be done.
c) for a car that has sat a while, a few things:
1) run it hard to get the tires hot to work out flat spots
2) add some PEA cleaner to the system for two full tanks (I use Gumout Regane HM; Chevron Techron has the same component though at higher cost/lower concentration).
3) I like to run a diesel/kerosene flush on ANY used car, switch to a Good synthetic HM 10w-30 (I like Mobil 1 HM). Add some Lubegard biotech to the oil. It will clean further and aid heat transfer, lower temps, clean up the narrow oil passages in these engines.
The other thing you MUST know is that the 4L30E auto trans (assuming you have it) is not bad, but it is not up to abuse, and is highly
intolerant of getting low on fluid. Read up on that and how to maintain it and you'll save some crazy potential hassle.
The Isuzu 6VD1 SOHC engine in your truck was used for years, and the later (98+) 6VE1 DOHC is very, very similar. You can find all you need to know about them here or on the web and people will help. So, welcome to the forum and if you want the help, you'll get it from the (IME) generous and knowledgeable people here. Ask away!!!