G'day mate. How'd ya like an answer from a bloody Ozzie on this? I live in Newcastle & built & race rally cars & buggies, with my nearest track at Toronto where one guy DID build a mid engined buggy based around a Common Door 3.3 V6. I think he may have used a Kombi rear end & geartbox, but ended up having to completely re-fabricate his own rear trailing arms. The car handled like a dog and the engine wasn't all that powerful. Lots of guys here have tried using that V6 because it's cheap & readily available. I know another guy who screwed one into his tube buggy to replace the Datto 2.0 litre he blew up. He literally - without exaggeration, had to buy & put together five motors to get one that finally was ok. He then sold that buggy which ended up being featured in the crap film "Tomorrow when the war began."
There are lot better motors out there just as cheap. Take a look at the one I'm building based around the engine AND transmission from a 3.5 litre V6 manual TJ Magna on my WJP004 You Tube channel (check my playlist). The Magna motor puts out more torque than anything else, and from racing the donor car for my buggy as a sedan for a year I can say they are literally a winning powerplant, and they sing on the rev limiter all day. Bloody cheap too as no bastard wants 'em! The Toyota Camry V6 looks good on paper, but I was warned off it by several pro mechanics as being unreliable. If Commodore motors were worth the trouble & good value for money you'd find them being used in serious offroad buggies in Australia, and in the pits I frequent anyone who turns up with one in their car gets laughed at and pitied behind their back. I also love Honda V6 Vtecs, but the problem is there's only autos in Oz - which COULD still be a viable option depending on what you wanna do with your creation.
Whatever engine you get - BUY THE WHOLE CAR. That way you get the wiring loom & mountains of other parts you can use like hubs, brakes, driveshafts & wheels. At the online salvage auctions at either Pickles or Manheim (just Google), you can buy a suitable donor car for just a couple of hundred bucks now as scrap metal prices have collapsed, re-birthing's been stamped down on, the scrappies have gone bust, so no-one wants anything pre-2000. Don't fall into the trap of building an entire project around some throw away car or engine. That is a recipe for a lot of heartache and a project that bombs out. Work out what motor & tranny you REALLY want - then go chance it based on your design, rather than the other way round.