My satellite radio is factory, but i have my cell phone mounted to one of these brackets that would work fine for your purpose.
I like that
http://www.panavise.com/ one the best. I've also used the one from
http://www.pro-fit-intl.com/ but it sits kinda low and can get in the way of the passenger (I still have it too). There's also one from
http://www.proclipusa.com/ but i don't really like the way that one looks.