try finding a gcx and ground control pro on ebay. I have it controlling my whole rack with TC G system, Digitech 33B ips, 2 gcx switchers,and soon to be TC 2290. I think you can do 8 different midi devices at once and 4 gcx switchers and 2 exp pedals. I also had a ART X-15 midi expression pedal that you can find cheap on ebay that might work for you. The ART has an output jack with a bypass switch that if I remember correctly could be momentary or on/off. Also has room for modding, I had mounted my Mesa MK III foot switches in it and made a cable snake from it to my rig. If you remove the 2 exp pedals you could mount a wah or vol pedal on it.