Harley touring mufflers are high quality and high flow. Went back to mine a couple years back. Found that after long rides me ears feel better, get better gas mileage, and bike seems to run cooler.
It's all personal opinion but I think Screaming Eagle slip-on's sound great. They aren't loud when you get on them either like some are. Just a nice rumble.
You need the modified stock pipes so you can adjust them to your liking. Contact http://www.americancustom.com/ and get the mid level baffles with them. If needed, just drill larger or more holes in the baffles until you get the sound you want.
I've got the Power Duals with the 4" Rineharts and I love the sound, throaty but not too loud.
Maybe one of your buddies might have this combination you could listen to?
That is what I am running on mine too.
Sound is perfect to me. I can hear the stereo just fine, but yet it has that nice throaty sound at the same time.
Sound is so subjective though.
What sounds "sweet" to one person, is just too dang loud or obnoxious to someone else.
When someone says try "brand x" you'll love them, in reality you may not like them at all.
I'm running a Zippers Max Flow air cleaner, Fullsac ceramic coated X-pipe and stock late model CVO mufflers on my 2010 Ultra. Still makes some sound with out being overly loud like some of the other slip-ons I used in the past.
I just put big Louie's on my bike, 4" 2" baffles. So far I like them. Nice sound when I get the gas and whe cruising the volume drops enough that I can still hear the radio.