The problem with 15's is the availability of anything worthwhile in something wider than a 225. They just aren't out there. I looked for awhile for something I could run on the cop rims I had on my Duster, and ended up just doing 225/60/15's all around. Wider than that and your only options are BFG T/A's and the MT's. Of the two the MT's have to be better, but compared to your options when you get up to 17" rims it's pretty sad.
If you really want good handling performance tires in muscle car sizes (that are street legal) you pretty much have to go to a 17 or 18" rim. I love the Toyo Proxes 4's I have on my Challenger, but again, those are on 17" rims.
I think the best option for good handling tires on stock looking rims are the 17" rallye and magnum rim designs from Year One. Still keeps with some of the original styling, but lets you really upgrade your tire options and handling.