I was Looking at different footswitches for the DS-2 pedal i think the one to use is the Boss FS-5L but i'm not sure is that correct?
Why do you need a foot switch for the ds-2 when it already has one?

So it can Change between the two distortion settings on the pedal without me having to bend over and turn the knob.
You can use any one button latching footswitch (like the Boss FS 5L)