Sadly, I contacted all of them after I was done with my H3's long travel was done. They are not interested. Brenthel, Total Chaos, Dixon Bros etc.
The don't focus much on 4wd, mostly 2wd stuff. However, we just need to keep on guys like Preferred Chassis Fab, am4x4, and others to build one. Just realize, these kits are not cheap by any means, so if you want something like this, you have to be ready to put down the cash.
Personally, I think we need to just buy one of the above mentioned 2wd kits and see if it will work with minimal modifications.