Where to buy thrusters for ROV/RC Submarine?

I' am doing a arduino based ROV so i need thrusters Any links to buy online thrusters for ROV/RC Submarine?

Build your own by potting a set of RC motors.

Making your own is usually better and in the end cheaper than buying some pod that does really fit your craft.
The few shops that sell subs on a hobby level only provide the most basic pods and at least I would prefer something that really suits my needs and uses parts I can get in any model shop.