Just go to Discount tire, they will hook you up cheap.. all 4 tires cost me $300 installed with new sensors. they need to be replaced every 5 to 7 years anyway when the battery goes out, and they go out more in Hotter areas of the USA then the north.. I bought a used Mustang with the light on, just one tire, they said battery is dead and if one is going they all are low if Original. Wish I had them in my Focus, low profile tire without them sometimes is hard to judge the pressure by eye and under hard turn I popped the bead from the rim and had to remount it.
BTW you can use either one now, they have universal sensors, they work with most systems and wont matter if they are strapped or stemmed. they will install them right