I would recommend the Lost Stories. The scripts for the year that was lost to hiatus are now available as finished audio episodes. It's quite interesting to hear what that series would have been like had it not been lost. (Interestingly, they are also recording scripts for other Doctors that were never done for television. I'm quite interested in "The Foe from the Future" myself.)
On the other hand, if you'd prefer to start with the normal range, there is a
list on Wikipedia of all the monthly releases, including which Doctor(s) feature(s) in them.
I see your point about Colin Baker appearing in more total eps than Eccleston, but since the modern show isn't serialized, I don't think one can think of a classic era episode in the same way you would a modern day episode. The classic eps are chapters in a story, whereas the modern eps are usually self-contained (except for the odd two- or three-parter), even when the series itself may constitute a larger story arc. My point is, Colin Baker didn't get a fair shot.