I purchased my Mighty-Vac Pump with gauge at Auto Zone for $25. I went to Wal-Mart and found the cylinder. What I purchased was an aquarium gravel vacuum with a diameter of 1.68" which will accomodate a girth of approximately 5 1/2". Since then I have "stepped up" to a 2" cylinder that will accomodate a girth of 6 1/4". These vary in price from $6 - $20. I made a guard for the base of my pump using a piece of bicycle intertube that I cut to fit. The hoses that were needed came with the aquarium gravel vacuum; the adapters came with the Mighty-Vac Pump. The pump I purchased is able to do both dry pumping and wet pumping.
If you need to find a tube larger than 2" you can check to find acrylic tubing and make your own. All it takes is some tubing, a sheet of flat acrylic, air fittings, and acrylic glue (you can do a Google search, etc., to locate these via the internet.)
This idea came from �other forum� Penis Enlargement Forum if you need more info. The guys there are real helpful.