I've stored pump gas with ethanol for 3 years on a double dose of sta bil. The heat expansion and venting caused a large loss in 5 gallon gas cans. Jerry cans, us style leaked fumes, NATO style deformed the Chinese copies the Authentic surplus ones did fine.

The next time I used liquid gasket on the seals of the blitz plastic cans, stored for 2 years, no noticeable difference.

These were all stored in a garden shed. And ran thru various motors, 350 w tbi, a isuzu 4 banger, lawn mower and a vortec 04 chevy. The 350 and the vortec were a little bitchy with the 3 year old stuff.

I've used L thanks, barrels, cans, and I still end up with a 5 gallon can and a cut transmission funnel.

There's square tanks from NPR trucks on craigslist that would work for a smaller bulk storage. Not much can be said about using an existing gas tank for a gas tank. I've gone thru that with hot rods and state troopers before.

All that being said I drive diesels mostly now. I buy ethanol free for my generators and power tools because I get tired of cleaning the carbs every time I put the thing up for 4 months. I even treat with stabil whenever I remember to before it gets stored.