dcgraves.com seems to have plenty of information on roller conveyors. You can also check wikipedia for more information and advice on roller conveyors.
you can find many great deals on quality roller conveyors at http://www.globalindustrial.com/c/material-handling/conveyors/roller-gravity and other sites such as http://www.hiroller.com/ and http://www.interroll.com/?wm=m(1526)sp(1500)
You can find a company that makes a pneumatic conveyor online at stores such as Aerocon, Flexicon Corporation and Vac-U-Max. Compass Systems and Sales also is a place that makes and sells pneumatic conveyors.
Try contacting other warehouses or warehouse companies to see if they have any old or used conveyors that they no longer are putting to use. If you want new, get in the phone book and look up companies. Do price quotes first then decide.
Used roller conveyors can be purchased in Shanghaideren, which is a manufacturer and supplier of conveyors, where the best conveyor equipment is available.
Roller bearing
The best website to buy belt conveyors from is www.gilmorekramer.com. They have a wide selection of belt conveyors to best suit the needs of your new company.
There is actually a company called automatic conveyor systems that sells the conveyors you are talking about. They also have product descriptions and good prices the website is www.automatedconveyors.com/.
Dematic pallet conveyors are convey systems that typically can support a heavy load and work efficiently in a variety of industries. Specifically Demantic is a company that manufactures pallet conveyors.
One can shop for a Roller conveyor online on several websites. One can shop for such items on websites such as Amazon, eBay, Conveyors, Grainger and IndiaMart.
The following companies manufacture material handling conveyors: Cemanet, Sriaariengg, Conveyor Handling Company, Thomasnet, Mheus, AGC Converyors, Shuttle Worth, Decon Conveyors, Kornylak.
Industrial belt conveyors can be sold to any automotive or electronic or industrial company that can take the item and either fix it up or sell it again.