Hey,
thanks for your advice! Mounting it between the bridge and treble could be an option although i would not like to go for that as is is recommended in the manual to put the gk pickup close to the tremolo. Thinking about it the roland pickup could be magnetic so i shall look into building a piezo pre-amp (for the graph tech saddles), although im not sure about the chances of finding a pre amp circuit with the specific roland 13 pin output,
thanks again,
Nick