Okay, so I'm thinking of buying some wheels & tires off tirerack.com and they give the option of installing new TPMS sensors on the wheels for you. If I get this option would I still need to recalibrate or set them up to be used with my Mustang? Or can I just swap the old wheels & tires for the new ones and the TPMS should work fine?
You need to recalibrate them since the TPMS sensors are calibrated to your car. Discount tire will do it for free, they did it for me. Not sure if the dealer will do it for free.
You could just pickup the tool yourself and do it. It's less then $20 and is only about the size of a keyfob.
Yes there is a tool and it's pretty cheap, too. http://www.allfordmustangs.com/forums/performancepartsinc/110472-tpms-calibration-scanner-tool.html
Yup, that's the one I have. Picked it up from a guy on another forum who works at a Ford dealership out in CA.