Here is what can be done to get a V6 MT75 2wd box

Just get one made up. 1 MT75 v6 4x4 box and 1 MT75 2wd Dohc box. Take it to a Transmission place hand over the 2 box's and about £100 +vat and ask them to 2wd it for you.
The basics are to remove the bellhousing, input shaft and the reduction gear. Then fit them to the 2wd box. This is the cheap way but it means using the Dohc gear ratios.
Or all the gears need to be changed across. This will cost a lot more.

Advanced Transmissions at Billingham did mine
One 2wd V6 box