PIAB sells T-slot adapters for their suction cups (you
are using a standard automotive industry end-of-arm tooling system, right?) which seems like it would be easy enough to modify into a standard mount bracket.
http://www.piab.com/Templates/WebBas....aspx?id=10183
Part number 01.04.111 (the G3/8") should be compatible with the FC75P.4E.07UF Suction Cup in the KOP. (Use email 'j.endira@ltcind.com' to access datasheets and CAD files.)
For quick reference:
PIAB part 01.04.111
Base: 1.25" square