Try these: Holroyd Components Ltd. | Tyre Warmers, Tyrewarmer Products, Tyrewarmers, Racetech, RaceTech, Raceready, Race Ready Not expensive and good quality - did I mention that I have a set and that I got them for free
always loads on motoforum,but you cant go wrong with holroyds.unless you want to push the boat out and get some cap-its
I looked into the best tyre warmers and out of capit which cost £320 Diamond £250 and thee above for a ton I got the holroyd and they are the mutts
also they have excellent back up,if you do get a fault,regardless of age(within reason) they will fix/replace FOC. had a 3 yr old set with a dodgey LED,fixed+delivered back FOC.