I think it's really easier than y'all are making it out to be. Width and wheel base are the only dimensions you need to be concerned about. The difference between 323mm and 335mm is only 12mm. That's about half an inch. You may have to trim a couple wheel wells, no biggie.

And why would you need to buy different body posts? Sure, you'd need to alter the height of the rear posts as they are pretty tall for the Dakkar body. But if you're talking about making it so the body holes line up with the posts, just drill new holes in the body.

The LCG HCG thing may not affect what body works.