You need the 3,175mm pinions. (Refers to the motor shaft diameter, 5mm are usually for short course or 8th scale)
http://www.hobbyking.com/hobbyking/s...-48_Pitch.html
Durango compatible spurs you can get from anywhere, RW are pretty highly rated.
http://www.rccarshop.co.uk/index.php...gear-8807.html
Have a bit of a rummage through the site, and see what you want size wise. (Micheal is one of the better Durango stockists)
As an aside, it *might* be worth getting yourself a pinion or two from a UK supplier just to get yourself going (unless you are already waiting for stuff!)