I simply fastened the stock whip inside my faring using ty-raps to several brackets inside. I attatched it to the radio with a short section of coax. Works great & there is plenty of room for both radio & CB antennas if you choose to use them both.
I bought 2 of these on ebay and used a "Y" adapter to hook them up together. I listen to my XM most of the time but the FM antenna's together work good.
I got lucky and found the last one at an Oreily that hadn't totally converted from a Kragen. You may have to do a search and find one. Try Amazon also.
Where in the fairing did you guys with the Metra antenna mount it?
To the inside of the fairing. The antenna has sticky pads. Also, my bike had an unused switched power and ground connectors on the harness going to the headlamp.