I can only tell you about the sena set up that I use.
1. Sena 20s
2. Sena sm 10
3. Zumo Gps
4 cord that goes from the din cord for hedset to 3.5 mini plug
You plug cord from headset plug to sena sm10 then plug a cord to zumo gps
I have an XM radio plugged into the mini plug in the left hand cubby and a thumb drive in saddle bag with music.
All devices a blue toothed together , this way any music source on bike and GPS are played to the sena 20s.
Also you can receive and make phone calls while on the road.
I know , I know it sounds confusing but its not really.
I have been using this for quite a while, and the 20s also allows you to communicate with other riders

that may be with you or your passenger . Now the sound is fine for me, others I think are too picky.