Yes got a t4,dont want it off ebay,like you say must have 3 year warranty. thanks.Got mine from here 5 weeks ago, full T5 kit with absolutely all the parts needed for fitting inside or under the van (although just noticed you may have a T4).
In my search for a supplier I did learn that it may be best to buy from an Eberspacher dealer with the 3 year warranty rather than from the Bay etc....
http://www.hallselectrical.co.uk/eberspacher-d2-12v-vw-timer-controlled-heater-kit.html#