This website has linear actuators, geared motors, track actuators , ect. The best part is, they are the least expensive I've ever seen! Also, they have a pretty large variety that come in 5 forces and speeds, from 28lbs to 400lbs force, or 2" per sec to 1/3" per sec speed. Even if you don't need any of their products, you should go check out their website, it's inspirational. They also have a UK Branch and they have a shop in Victoria, Australia.