^^ Agreed, TPMS warning lights cannot be dissabled (federal mandate all 2008+ vehicles need TPMS sensors). My engineering friends (also car guys) said that I was dumb for not being able to figure it out and after about 4 hours of research they agreed with me.
Any focus can use Band Style or Vavle Style as long as they are 3400 MhZ they just need to be "trained" to the car. I got a set of valve stem TPMS sensors from a member on here to throw on my after market rims once I change out the tires.
If the light on your dash showing "low pressure" doesn't bother you then don't worry about the TPMS sensors, but if it does it'll cost ya ~140 to buy them. Usually shops install them for free if you are getting new tires but if they have to break the bead and mount them I think it would cost around $30-40/wheel (120-160 total).
If you can't wear it out, burn it off