I know this is probably a well covered topic, but with all the possible combinations of products involved, I'm just going to ask it anew.
The situation: I have a bike set up with an 8 sp. SRAM cassette, a Shimano 600 rear derailleur, and 7 sp. index shimano downtube shifters set to the friction setting. It works well, but I recently picked up 8 sp. ergo Campagnolo shifters that I'd like to put on the bike.
I know the easiest thing to do would be to pick up a campag derailleur and use the shiftmate, but in the short term, I'm thinking of using the ergo 8 with my shimano RD, and adjusting the spacing of the cogs on my cassette to accomodate the combination. This product (http://www.branfordbike.com/cassette/cog12.html) required the shifters AND the derailleur to be Campag, so may not be exactly what I'll need.
And so, the question: Has anyone here had success with this scheme before? If so, any hints or suggestions? Am I aiming for the 5mm pitch spacing required for a campag set-up, or something between this and the 4.8mm shimano requirement?