I run petrols becouse they are cheaper to get hold of, costs about the same to run as a terbo deisle (when it's being driven carfully, ie not on the terbo all the time) and has about the same performance.

1) The petrol does cost a little (and I meen very little) more to run fuel wise. However as a petrol will on average cost you about half to two thirds the price of a deisle in the same condition you can afford a little extra fuel.
2) The petrol will out run a non terbo 2.8 deisle, and will keep up with a terbo up to about 50mph befor dropping back. She'll still do the same top speed, but it'll take her a little longer to get there. But remember while the terbo is working that hard on the 2.8 it's owner could use the fule needle as a fan with it dropping that fast.
3) Towing she will start to feel the lack of deisle grunt, but only on the up hill sections. You'll need 4th or 3rd, where the terbo 2.8 will keep pulling 5th. On the flate she won't lose out much at all.

I sugest having a profesional cheke out any car you are looking at bying, if your not happy with your own jugment. However generly if a fourtrak has a good body on it, the rest is probably good too.

Off the top of my head I'm not sure if the fourtraks of that age have a 100'000 mile digit on the milomiter. I have a nagging suspition that by that time they did though. I know my B reg doesn't. But then she's as old as the F80 (or 85) gets in this country.