If you can get fuel from a local airport, 100 octane low lead has no ethanol in it, and has no storage issues.
It's going to run you at about $6 a gallon, and their not really allowed to sell it to you for this, but it happens.
If you know a pilot, it would be easy for him to get you some.
We used to have drums of 'waste' fuel, that was drained from our aircraft during service. Nothing wrong with it, but it could not be put back into the planes. If you have a small aircraft hangar nearby, they may be willing to sell it to you for cheap.