It looks much better on a Camaro, doesn't exactly fit the muscular lines of a mustang. I'd think a coupe without a roof but with full length subframes would be stronger than a convertible with the halfass subframes that come stock on it.
If you're thinking of buying something made by JMS Products Inc. be careful. I order some parts and it took 9 months to finally get the parts, and the quality is quite bad. I've had several body shops look at the panels I bought and they all commented on the poor quality. There's another company making these sorts of parts - I'll try to find and post here if anyone is interested.
I got burnt by these guys and will not ever refer anyone to them. Bad service, bad quality, long waits. They're unorganized, and just not ready to start a business.