When I wanted to outfit my 9 speed triple (with a 26 or 27 large cog) as my brevet/touring bike, I just changed the small front chain ring to a smaller size (pretty sure it is a 28). A lot easier and cheaper than switching the back and it give me plenty of gears. Cost me about $50 ordering the touring ring off Peter White's site.

(This may only be able to be done with Campy, but I don't know why that would be.)

I ride with lots of folks who have compact doubles paired with SRAM or Shimano MTB rear derailleurs and dinner plate cassettes.