what to do..suspension lift?

If you want to be doing some extended trips in the future,,,, good luck finding the room in a swb vehicle......

I'd be staying with the GQ if I was you, its bulletproof, more forgiving as you gain that valuable experience and doesnt need to have a lot spent to become awesome offroad, tricking up a Paj to do what a GQ does std will drain the bank faster that the GQ eats fuel...marginally, go get a gas convo on the GQ.Laterally Literal
Seriously Cerebral

Rino,
Personally I would stick with the GQ idea, you know the history of the fourby for a start, being your dads, if you spend your hard earned dollars to buy something off somebody else you could well be buying more problems. As others say the GQ is tried and tested and virtually bomb proof, spares are plentiful so is advice as you can see. the IFS doesn't give you as much to play with as does the live axle on the GQ.
Your choice also depends what you are buying the vehicle for, the off road ability of a vehicle isn't completely the ability of the vehicle, the driver plays a major part in this process as well, a little bit of training and experience helps. Join a club don't try to learn on your own it can prove costly and in some cases embarrassing, it's much better to learn in a group. Insurance is expensive and one reason for that in a few cases is inexperienced drivers taking risks and loosing the lot for one rason or another.
My opinions as usual, hope some of this makes sense or helps. Good luck and happy driving.Keep the shiny side up

The patrol is ultimately better offroad than the pajero, due to its live axel set up both front and rear. However front inderpendent suspension is not without its advantages, it makes for a better ride on road, and for touring it is certainly alot more forgiving than live axel. The right suspension lift for independent will compensate for limited travel. If your really keen you could remove the anti sway bar and squeeze a few more centremetres of travel out off the front suspension, just don't tackle corners too fast. Short wheel base 4wds will make better offroaders, as they have better departure, approach, and ramp over angles, the only set back is the limited carrying capacity of these vechicles. You mentioned that you intend to do some serious offroading, weather you go for the pajero or the patrol you will have to at some stage look at a suspension lift. It all narrows down to where you spend most for your time driving. More offroad driving then i recommend the patrol. However if your after a good compromise between on and offroad driving the the pajero is the pick of the pack. they offer better onroad performance, while they won't tackle hard terrian with the easy of a patrol they will go as far, and with the right suspension lift, and diff locks the pajero will confront difficult terrian with the same poise as a patrol. I haven't pesonally driven a 3L pajero, but I have heard they can be short of some leg at times. I would imagine the ecomony would be alot better than the patrol.
Hope this helps, if a bit long.