Canuck....I have a 09 Road Glide and replaced my whole system (except radio) with amp and speakers from Peter Jensen at www.soundzcustomz.com . I can't say enough about their products and customer service. I am now looking at replacing my HK with a Sony MEX-M70BT radio so I can download music to a USB drive and don't have to carry cd's with me. Check out their website or call them.
I did same thing on my '11 SERGU. Word of caution, with the MEX-M70BT, you cannot see the screen in the daylight due to the angle of the fairing and the small screen. The sun glare makes it impossible to see and I even had a rough time on cloudy days. I'd suggest after going through this, you send the stock HK head unit to Iron Cross, they can add BT and RCA Preamps to unit so you can plug in the new amp directly to the HK unit and you can listen to the music on your phone or IPOD if it has BT on it, most new ones do.
For some strange reason, HK units only put out 3 amps on the IPOD side, if you get the RCA plugs, it increases it to 7 i think was what I was told. That will make a huge difference in sound output.
Agree on Pete at Soundz, great people and I blew three Focal speaker over three years, had AVC too high probably and they sent me new speakers each time with no questions asked.