[460 mustang]

I got a 94 XR-7 3.8 Cougar with 44,000 miles, got it about 5,000 miles ago. It recently blew a couple holes in the catalytic converters, right where the pipes are welded in off the exhuast manifold, and to the rear where the output pipe is leaking at the weld. I know I can take it to a shop and spend hundreds for labor, but has anyone had this problem before? It is in a Y-pipe configuration, and to replace one, I need to replace the whole assembly, as well as the muffler. I guess what I'm trying to say is, has anyone had this happen before, and if so, what did you do? Did you take it to the shop or do it yourself? Also, about how much did it cost, because looking at the prices online, I'm expecting $300-$400 no problem. If anyone fixed something like this, did you go with an aftermarket setup, one that is supposed to fit in place, or an OEM setup? If so, please post here, I'd really appreciate it. Thanks!