Re: Fuel tank sizes?
Go as big as you have room for. I typically use motorcycle fuel tanks that exceed 2 gal. No need to worry about "gel packets" (not sure what that is), just run as big a tank as you want/need.
Check around and see if there is a motorcycle salvage yard near you. You'll have plenty to choose from and only have to worry about how to mount them to your bike.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"