With the Savage SS you have to provide your own radio gear. Usually you will buy a whole setup for it. If you already ahve your own electronics for it than yeah you can get one at either your LHS or Tower sells them pretty cheep.
It works well and is what I install on all of my rides. One lead goes to your hump pack, another to your receiver and the 3rd lead is so you can hook up your charger. On my Savage, I let the charging lead hang out of the front of the receiver box so I dont have to open it up to charge it. I used the dremel to round it just enough (maybe an 8th of an inch) so as not to pinch the lead.