Dear Shboom
I can empathise with your live difficulties regarding the sounds you would like to make and the equipment you are used to using to get the "right sound".
I can remember being on tour with Gloria Gaynor in the mid 80s - we were scheduled to do a gig in Guernsey (a small UK tax-haven island just off the coast of France) that was billed as a premier nightspot. We had to take our frontline gear (synths, guitars and such) and the venue woould supply the backline. We turned up at the venue to be greeted by 1960s Ampeg guitar amps and bass speakers (hardly the correct amplification for Korg Poly 6s, DX7s and the like), and frankly it sounded dreadful (certainly from an on-stage point of view!)
However it was considered one of the beat gigs ever done on the island at the time - I suppose that the moral of this paricular experience is that although the gear might be less than serviceable, the result is usually OK from the perspective of those customers who have no inside knowledge as to what is achieveable, or what is the "correct" sound structure.