The idea itself should be fine.. There are quite a few people here running just the resonator and no mufflers at all.. The SVT mufflers are a straight-through design, which doesn't do much muffling..

I replaced the resonator with a freer-flowing resonator that Meineke carries, more authorative tone w/o any rash or riceyness.. I kept the SVT mufflers because the entire combo sounds perfect right now (anyone that's heard my car in person will vouch for that), so why mess with it?
When you remove the cat, I tbink you're going to introduce some more noise/rasp.. That's my main concern in going to the MSDS headers, I'm not sure how loud it's going to get. Good luck.