polarbear,
The cockpits of most Catalinas are pretty much the same size. Why? Because one of the "hallmarks" of Catalina's design philosophy is that one should have a cockpit large enough to sleep in/on. Really.
The cushions from our C22 fit perfectly on our C25. Our C34 "bench" seats are not very much longer.
I actually think you'll find that Catalina's cockpit seats are among the longest in the industry.
One thing to remember and to look for is a comfortable backrest, meaning that the coamings meet the cabintop at a right angle, because if they are curved, as some other builders make them, simply sitting back is NOT very comfortable. We bareboated a few Beneteaus, for example, that made it impossible to lean back because of the curve between the coamings and the cabintop.
You'll also find that larger boats with wheels may make for more cockpit "room."
Good luck.