I ended up going with a regular Magnaflow, 21" or 22" on my 07 V8. (The original muffler and resonator were cut out as one section, I'm storing it in my garage in case I want to return the exhaust to stock setup for resale purposes.) Earlier I had dual stainless steel tips installed and rear pipe section replaced to bring it up closer to bumper.
Sound is very good at full throttle, reasonably subdued at moderate throttle and cruise, only slightly louder than stock at idle. So far so good, it's only been on for 2 weeks.