Browsing on Google, was searching for a source of suction hoses. If nothing else, you may wish to add this link to your equipment sources. They appear to be at least 25-35% less expensive than a lot of sources I've made inquiries to. Or just google "Car wash vacuum hose" in quotes to narrow the search parameters.
As a matter of fact, I've ordered 20 feet of KA112CL-4 industrial strength flexible helical suction/discharge hose for $4.77 per foot plus trucking freight from Ohio. In the end, I paid about $10/ft., delivered to my door without sales tax. Not bad, considering most places are charging $10 - $15 a foot + freight. No calculator may be required to do the math. The 6" clear is $10.50 /ft and the 8" is a whopping 18.70/ft. plus the freight. I haven't seen a single offering for 7".
http://www.dultmeier.com/products/0.2006.4388/1693
KA-110CL-3_4-Suction-Hose.jpg
Thanks for the Great Website I would never thought that 7" hose would be that hard still looking wish me luck
Yours in Peace
Michael
RE: Good hose source on the web