www.petzl.com has professional/recreational climbing equipment for every need.I don't know if they sell directly to the public but Mountain Gear is one of their retail shops.
Climbing at MountainGear.com
here's the pulley section
http://www.petzl.com/en/outdoor/pulleys for recreational lightweight climbing use and pulley section for heavier professional use
http://www.petzl.com/en/pro/pulleys
You should ask a fireman/EMT about their sources of equipment because the light weight aluminum climbing equipment could be more expensive than some made of steel.