On a plus note they do use the same bolt pattern and offset as the Mustang, so a lot of choices there...
KMC will make you a custom wheel, just takes a while to get them. I ordered some XD series Hoss 20x9 for mine not too long ago. Going on two months now.
And BTW OUTKAST, your factory rims done in flat black look HOT! Got any bigger pictures? You said it was cheaper than new wheels? How much did the powder coating cost? I checked on doing mine in black, cheapest estimate I could get was around $150 per wheel and that was PAINT, not powder coating. That's why I went with custom wheels, got mine for $250 each tax included, then again I have a hook-up at NTB, so I pay 10% over their cost.