Underdrive Pulleys

[Sidzrx]

I\'ve just refitted the air pump to my car so it will pass the MOT, and have decided I want to keep it on.
However I have a set of Greddy underdrive pulleys and would also like to keep these on the car as well.
So is it possible to get a belt that is long enough to run the underdrive pulley kit and the airpump, or am I gonna have to make a choice?