I really like the spring reverb on my main amp but its a dial which makes it a PITA to turn on and off in the middle of a song.

I've tried a few different pedals, haven't found one that I like anywhere near as much yet.

Was wondering if it was possible to turn the reverb knobs into switches? Its a fairly subtle reverb as it is and when I use it, crank it anyways.
Most of these amps have a foot switch to do exactly that. Do you know if there's one available for your amp? Is there an input in the back of the amp for a switch?  For example, I have a Carvin Quad-X like this one, and that's the switch for reverb, third from the right. 

It's a dual reverb Peavey XXX Super 40. It has the original switch. Its only has buttons to switch between channels and a volume boost button. Peavey's aren't known for having reverb switches.
It should be pretty simple to add in  a simple toggle switch before the signal goes to the reverb knob, probably just one wire signal. I dont use reverb amps so I cant say for sure. 

If it cuts the signal completely , as in no sound at all, then you might need to use a 3 way switch or some sort of dual path (cant think of the technical name) switch.