Classic sue has a very similar conversion to GUT, I had also just assumed that both these conversions were using TD hubs and outer portal "faceplates". I never bothered to find out the finer details because their prices were way more than I'd be prepared to spend.
This YouTube screenshot is of a mad Russian 712, I posted I link to his build a few months back in a thread I called "highly modified 712".
- Screenshot_2016-02-01-00-14-50.png (616.9 KiB) Viewed 5986 times
A pretty simple solution BUT this design made the track significantly wider so he now runs Hutchinson beadlock wheels and he has widened the 712's body by 200mm so the wider wheelbase suited his overall plan. Also important is the fact that the lower (IIRC) bearings in each of his portals only lasted 1000km because they couldn't stand up to the extra load that widening a wheelbase causes, the solution was to machine the portal to accept a bigger/stronger bearing. Apparently this worked as he says in his build thread that he has since travelled many many thousands (over 10,000 IIRC) of km's without issue but it does show that every action has an equal and.......you know the rest. So any kit really needs to be well thought out from all angles.
If a kit was to be put together my preference for its design would definitely be for the GUT and Steyr approach of supplying new hubs, portal "faceplates" and probably wheels too. One improvement I would like to see is a beefier vented disc especially up front but for parts commonality probably use it all round, and it really needs to be an "off the shelf" easy to get anywhere disc.
P.S. I have no idea why "fantasy fest 2015" would be recommended for me
I didn't go that year 
