So the procurement and design stage is going well and our new team has made a good start; however I am having a nightmare with sorting out the belt drive system - where can i find pulleys/sprockets?

I am looking to get a 7:1 / 8:1 ratio using pulleys - preferably with a toothed belt. Building a bot with a strong pushing power; from viewing other bots i have learnt those with a belt drive are better when it comes to self preservation (allowing slip and less back emf issues with the motor).

Currently have 10 inch wheels / 3300RPM motor and looking to get 15mph drive.

Any direction in this area would be much appreciated!