hmmm, If your dead set on electric (or dont have room under the hood for a YORK) then I would go with Viair. Either the 450c (sealed unit) or the 550c (unsealed, but higher CFM).
They both draw about 30 amps and have 100% duty cycles at 100psi.
OASIS makes an electric unit, but they draw some SERIOUS current and you would need basically welding cable to run them.
20 gallons is gonna take a LOOOOOONNNNNG time to fill with an electric unit.
Really, a YORK is the way to go. 11cfm, no battery drawdown, but only works when the engine is running. A viair will prolly run for a little while but will draw the battery down fairly quick.
The problems with the YORK is, no one makes a braket for our trucks. All the guys that have them had to make their own bracket. You also need to weld an additional pulley onto your existing pulleys and run a second belt.