Re: Footswitch question
Depends on the jack at the amp, which should be stereo (but you never know!), but yeah, any 2-button switch with a stereo jack and a TRS-to-TRS cable should work.
Don't recall the model #, but there's a Digitech footswitch that's 100 years old, encased in steel, and comes with a 4-mile-long TRS-TRS cable. They're generally cheap on Ebay - don't even know if they still make them - and can work with anything that will plug into it.
Another point to consider - if the original pedal is set up so that it selects between Clean and FX with one switch, and OD1/OD2 with the other, you might have trouble if you get a 3rd party pedal where the switches turn each other off. Try to kick on some chorus or FX for that solo you're about to break into and you get a chorus/FXy clean tone, or you try to kick on the chorus for the clean and go into OD2 while strumming a GMaj7.