My suggestion on this would be rip out the 8v engine, shove in a 16v redtop from a Calibra and have it properly rebuilt before hand as the 8v is too slow to do the job nicely.. I would also suggest that you get the Calibra ECU to go in as well. Don't bother with the 16v Turbo from the Calibra, it's not worth the extra agro to fit it and upgrade the front axles etc etc etc...
You'll want the roll cage etc...
Ripping off the back isn't a problem, make up a nice frame behind the roll cage rear mounts and weld in your bulkhead, as you're not looking for looks it could be done fairly functionally with a perspex rear window.
UPGRADE the front radiator, twin electric fans (as the motor won't want to have one on it drawing BHP)
Upgrade the front and rear suspension, probably looking at getting the front wound up a little then RE-SET the torsion bars, just putting in new rear springs and some extended shackles will help, with all that you can get a 4" lift with no really dramas.
With the 16v engine you would have more power than suzuki/LR etc without a doubt, you unfortunately have a lot more weight than the suzuki, but you can remove a LOT of stuff to make it lighter.. such as removing much of the interior and replacing with alloy chequer plate etc, things like door trims might only weight 2 or 3 kg each, but that's 6 kg for two, plus all the interior of the rear that you'll be ripping out.. you can change the seats for something lighter and more functional like Carbon Fibre racing seats etc..
Remove the front bullbar, or at least cut it down so it's only he centre section up to the top, ie cut off the bits that go out over the headlights, they would bend in and destroy the wings anyway and they just add weight.
Make sure it's not got a tow bar etc. Remove the rear bumpers and replace with some alloy chequer plate to cover the area. Removing the rear wheel and mount off the tailgate and replacing the rear wheel in to the tray in the back of the new pickup.. Removing EVERYTHING from off the rear tailgate so you've basically got a bare shell with an outer skin on the back and alloy chequer plate on the inside..
There is STACKS of stuff under the bonnet that can be removed easily.. and to help with weight distribution you can move things like the battery back in to the rear of the vehicle, along with the air cleaner box so that you can get your air feed from above the roof line of the truck and not suck in the dust that usually ends up in the wheel arches..
If you wanted a few more ideas drop me a PM and I'll keep going. I could just keep on making suggestions, but if you seriously wanted to do this I'd be willing to help out with trying to set it up..
Get your shock absorbers from Old Man Emu or similar in Australia, I can give you a list of suppliers... you want shockies which are built for TOUGH terrain, ES9000's aren't really built for the sort of thing that you'd be going through constantly, they may be good but OME's will outlast them, there are a few other good bits you can pick up easily from Aust and have it all shipped at once.
PM me as I said if you want me to keep going and give you a break down of bits and pieces to remove, bits and pieces to fit and how to get it all done properly.
Cheers,
Si
Watching this thread with interest 
