Congrats on the bassanis. As far as mufflers go I'd say which ever ones you like as they are all 1 3/4 inch head pipes you will have to make a set of support brackets for them though.
Maybe a set off a touring model would be best
I have 2005 Silverado with hard bags, and currently I'm planing some further mods.
If I get it right - once I have a set of Bassani duals on my Roadie, I can go any HD mufflers ? IE : Bassani 4" Slant Cut Slip-On Mufflers
The only issue is to forge propper brackets ?
I know there is cheeper stuff out there, I just think this slant-cut end would go nicely with RS