Take a look at the SAS website, news relase dated 1 Dec 2006. It seems pretty clear that they will be using a 902:
http://www.specialist-aviation.co.uk/news011206.htm Air Ambulance Service for Surrey and Sussex - A Step Closer
"Kent Air Ambulance Trust has selected Medical Aviation Services Ltd. to provide an MD Explorer which will be based at Dunsfold from early next year."
There could easily be a short term interim solution, but the final aircraft is pretty clear, especially given the operator and the AA trust involved.