Mustangs are probably your best bet. With most of those rims though you will need to either dremel the hub bore of the wheel or turn down the nose of the hub on your disk brakes in the front. The OE Ford hub more is a couple mm's smaller than the disk brake hubs on these cars.
You may also need to use a spacer in the back, the BBP 7.25 and 8.25" rear axles are pretty narrow and the Mustang rims will have a decent amount of backspace. Depends on how wide you go with the tires and which rim/model year you grab. The problem with the A-bodies is that the backspace needed front/rear isn't the same once you go wider than a 225 for a tire.
