Thanks for the confirmation JakeC, it's good to know I'm not losing it! I really try to plan things out and do my homework first and your comments reinforce what I've read elsewhere.
On another note, after much hemming and hawing and some sound advice from Tango, I finally settled on my propane tank. I decided to go with a single tank. It's a Manchester 11.2 gallon permanent mount, should be plenty big enough. http://www.dyersonline.com/manchester-1 ... -tank.html
The mounting went nice and smoothly.
There are four 1/2 in galvanized bolts holding it in, nice and secure. I did multiple scientific/engineering tests to make sure it was strong enough...at 175lbs I jumped up and down a few times and it didn't budge! Good enough for me!!!
Here I marked and cut out space for an access door.