Did you get your truck new in '07 or did you just get it used? If you just got it used, you probably have XM but just have to activate it. I got my truck new in '07 and it came with a few months free service. If you hit the band button a few times you'll scroll through the AM, FM and eventually the XM channels. There will be an Id number that you have to give to the XM people on the phone in order to activate the service.
If your positive you have no XM, I would check behind the glovebox, where the XM tuner would be, and look for the antenna and interface connections there. Even though you don't have the XM tuner installed, which is kind of wierd, your truck might still have the wiring for it. If the wiring is there, it's probably labeled too. The tuner will plug rught in.
When I did my Kenwood install, I swapped out the XM module for Sirius. If you haven't picked one up yet let me know, I'll sell you mine for $50 shipped. The one in your link says '08 and '09 so it might not work in your '07. Let me know and I'll send you some pics.