I have V&H Powerduals with Monster Ovals, SE Air Cleaner and a HD Race Tune. Setup sounds pretty mild to me. What Mufflers could I switch to for more sound, but still be able to hear my radio?

 

You've got to decide between the two if you still have the stock head unit with no amp and/or updated speakers. If you upgrade to be able to hear the speakers, you won't hear the exhaust and vice versa.

 

^This.

That being said, you have a set of the mellowest mufflers out there. Changing them to something like the Bassani DNT's, or for louder but the same tone CFR's would be my choice. Both of the mufflers I mentioned are on the quiet side while cruising (the exhaust note is really deep) and you may* be able to hear your stock radio. It sounds like time to get louder mufflers and a set of speakers with an accompanying amp!