Well, I doubt EVH used much reverb, mainly alot of gain which would give you alot of sustain.

Reverb and distortion(high gain) generally don't groove well, from my experiences. Smooth overdrive and reverb CAN work together. Usually I keep the reverb on my amp at 3 or 4 for anything with gain, and for certain tunes, and clean only, I'll crank 'er up. But I also have Fender Tube/Plate Reverb.

I would go with a Reverb OR Delay pedal.