EVO Jet looks interesting. I couldn't find any sort of demo online. If you use this, perhaps you could tell us if they report the prices from contract fuel providers, and then let the user buy through their own accounts, OR if they are acting as middleman in the transaction.
In other words, where does EVO get their money? FuelerLinx charges a monthly fee of a few hundred bucks, and users have arrangements with the contract fuel suppliers.
.... Flying is the easy part!
FR