YEP you can get their barrels about anyway you want them. When I ordered my 15" Stainless-Steel 6mm T/CU from VVCG's, Steve and I discussed Rifling Twists, Forend Dovetail Spacing, Throat Dimensions and a lot of other options. In the end I ordered my 15" Barrel with the Forend Dovetail Spacing for the Super 16 / Carbine Forends. Once the Barrel arrived I just opened up the barrel channel to free float the forend, and I was good to go.
Larry