Lui, without changing wheels, I think your only option would be to use a 255/40-17 in the front. You can go wider, but they get too tall, IMO. I'm not aware of anything that's available in a 35 series, until you get up to 295/35-17, which would require at least a 10" wide rim. If it's mainly appearance you're concerned with, and you don't want to buy new wheels, the only option I can think of is using spacers. It's not an ideal solution but it can work safely if done properly. Before people get upset with this suggestion, keep in mind the factory fitted spacers on GT5's and Porsche has been doing it since the '70's. The correct way to do it is to make sure the spacer is tightly hubcentric and also make sure you're using the strongest wheel studs possible, with adequate length. This likely means having custom spacers made and be as conservative as possible in deciding on a thickness.
Mistersolo, yes, if your brake rotors are mounted on the outside of the hubs, you need to add the thickness of the rotor hat to your backspacing or offset calculations. Also, the Pantera's wheel registers (hubs) are slightly tapered, so if you mount your rotors on the outside of the hubs, the diameter of the wheel's center bore must be slightly smaller, in order to maintain proper hubcentricity.