All of the dish truck wheels that we make are the exact same offset. All of the new part numbers are in the GT2 catalog.
The fronts are all the same between GT2, T4, etc...
For the rears, you can run the 7847 white and 7851 yellow dish rear wheels with wheel nuts on either a T4 or GT2. For the GT2 to use wheel nuts, just switch over to a T4 CVD kit with the same wheel spacers and everything. The GT2 1.5 deg hubs are the same bearing spacing so you only need to put in the CVDs.