A Magnaflow cat-back and an X-pipe would probably be a good start towards the sound you're looking for, IMO. An X-pipe makes things sound a little less "chunky," gives it a slightly smoother tone like the 4.6's. Another option would be some Dynomax Ultra-Flow or Hooker Maximum Flow mufflers with tailpipes behind any X-pipe - all pretty similar in design.
If you want something of about the same tone, but a little more ballsy, go with what I'm running on mine (Pypes Violators and off-road X-pipe). Gets lots of compliments, and it doesn't have the obnoxious Flowmaster drone, sounds pretty civil in normal driving, sounds like hell on earth when you go WOT.