I’m toying with the idea of a street licensed, off road buggy, that is SUPER light. Kind of a street legal side by side. Work sends me to different locations for months at a time and miss my toys while at my work assignment.  I want something that I can put on the back of a flatbed truck. While loaded on my truck,  I do not have to be to terribly concerned about parking / storage. No lift, so it keeps a low(er) profile while on my truck. As long as it is on the back of my truck, I think I can park in most parking lots / streets.

I’m considering what platform to start with.
I’m thinking Gen2, stripping the entire body off, having some sort of rollbar(s) welded up. I’ll retain firewall and maybe windshield. If no windshield, helmets and air pumper.   Trying to get down to 1600 - 1800 lbs.

Considering a Grand Vitara  VS.  Vitara with maybe 2.3 liter swap.  If  I started with 2 door, 2.0 liter Vitara, front bumper to rear axle is about a foot shorter.  I haven’t decided if 1 foot shorter on the truck is a fair trade off for the longer wheelbase on the trail.

Does anyone know the  weight difference of a 2.0, 2.3 and V6? More than 50 lbs?  If I reach my 1800 lb goal, would I be better served with stock 2.0 (lighter)? Do I need HP and torque V6 offers?

Drive train.
Are there differences in V6 VS 2.0 drive trains?  Should I care?   I’d consider a rear locker and maybe crawl gears at some point.

Trying to keep suspension, drivetrain near stock. Repairs on the road with limited tools will be easier.  I know this will limit my capabilities.  I’m thinking “exploring” not “conquering” .

Weight - the difference in weight between a four door gen 2 with a V6 and one with the inline four is a shade under 200 lbs - the 4 cylinder four door is listed as 2866~3020 and the C6 as 3064~3197, my guess is the bulk of that will be the engine & transmission.

Drive train - if you're looking at manual transmissions the V6 model uses a different, larger, heavier transmission, if you go automatic, both use the same 03-72LE four speed automatic.  I believe the transfer case on the V6 manual transmission model is unique to it and gears may be hard to find, I think the four cylinders share a transfer case with the earlier models and gears should be available, axles are for the most part interchangeable, but, and this may be important, late model V6 models with manual transmissions came with a cast iron front axle, all others are aluminum, and easily broken.

Thank you for the information. That is exactly the kind I am looking for.  I have a few parts already. A 4 cyl manual transmission and transfer case. And a complete 2wd 6 cyl donor GV. I wonder (thinking HP : weight ratio) if I go with the V6, would I "need" the heavier front differential. Which all adds more weight. OR would I be better thinking light, light, light.  2.0 liter, manual trans, alum front dif. If I added crawl gears, that might be the time to add the heavier front dif.

I'm still pondering a 2.0, 2 door donor for a shorter wheel base. IT would fit better when loaded on the truck. Pondering how much stability / capability I give up over a 4 door frame. Admittedly, I already have a 4 door frame, so I'm leaning that direction. If I went with the 2 door, it's quite possible I'd upgrade to a 2.3 liter engine.

My x90 weighed 2450 lbs with a half tank of gas!

2-door, 2.0L, 5-speed, steel front diff, 5.13:1 diffs, 4.24:1 low-range, lockers, and some 31-33" tires...you'd be unstoppable until you flip over backwards going up a steep hill!

Something sort of like this but more stripped down: http://www.fourwheeler.com/project-vehicles/1309-two-day-1999-chevy-tracker-build/

My 93 2 dr with V6 5 speed Automatic, 33" toyo tires, winch, heavy duty front bumper, roll cage weighs 3250 with me in it, so 3025.  Which is on par with the newer 4 dr.
I think getting down to 1800 street legal is somewhat unrealistic.
The aerio 2.3 motor shouldn't weigh any more that the 2.0 and give 40 more hp, with better low end power.  But cots are more.

Been to Moab on 30" tires & 33" tires, 33's are better, and more power is more better.  I have arb's on both ends and having selectable diff's is a blessing on the sandstone.  Being locked on both ends it really wants to go straight.  I have been up some pretty steep hills, without fear of flipping over backwards, although when all you can see is sky out the windshield the pucker factor goes up when it seems to get even steeper.   Going down the steep inclines has more possibilities of flipping you over as there is so little travel on the suspension that when one corner drops it lifts the opposite back corner into that dangerous area.
The lower gears in the TC is a must for serious of road, and very helpful at Moab.  (While I don't have lower gears my 5 speed auto does have lower first gear, and over twice the power of stock.)

I would say wheeling almost anything will be better than figuring out the perfect trail thrasher to build, but having a goal is a good motivator.  Even stock these are fun off road.