Toyota Repair: toyota pickup 4cyl vs. 6 cyl, head gasket problem, decent gas mileage

Question
I am in the process of deciding exactly what type of toyota pickup to buy. I know I'd like an older (1990 -1994) 4wd model, primarily because of cost. Basically, I'm after a reliable, get-anywhere, last forever but modestly decent gas mileage sort of light pickup.

my question is this: is there a significant difference in reliability, ease of repair or any other factor between the 4cyl and 6 cyl engines? What sort of effect does the difference in power have, ie does the 4 cyl only crawl up grades? I wont be doing much, if any, towing.

a related question: is there any difference in reliability/reputation between models of different years (late 80s to mid 90s)?

one last question: I'm assuming that I should avoid any truck with a rebuilt engine. true? or does that mean it will last that much longer?

any other info/tips on the properties of these trucks is appreciated.

Thanks a bunch!

Answer
There are a lot more V-6 powered trucks than 4 cylinder versions and I think that Toyota stopped 4 cylinder production in 1991 or 92, the V-6 engines had a head gasket problem, there was a special service campaing to take care of this, that means that the factory paid for headgsket replacement one time, unlimited mileage, these engines are still prone to head gasket failures so it would be a good idea to see if the SSC had been done on any V-6 truck that you consider buying, you can check with any Toyota dealer for this information.
Some of the 1990-1991 engines had valve problems, the valves would deform and strech causing compression loss and engine misfires, chances are that any truck of that vintage has already had the repairs done or had a rebuilt engine installed or other major engine repairs so you don't need to be concerned buying a truck that has a rebuilt engine.
There is not much difference in power between the two engines, the v-6 has a little more, both have excellent pulling power in low 4x4 and will go up almost anything(I own a 1990 4x4 4Runner V-6)the trouble areas with the 4 cylinder engine are headgaskets, cracked heads and the timing chains(they wear out at about 90,000 miles)on the other hand the v-6 uses a timing belt which is a lot cheaper to replace every 60,000 miles.