It is quite an old thread almost old enough to drink. In the end the bottom bracket is dependent on the cranks pretty much exclusively aside from getting the threading and width correct for the bottom bracket shell but the actual manufacturer or model of the frame is pretty much immaterial. I could have Trek Blah Blah and a Bianchi Doopty Doo and Specialized Thingamabober and if I put the same cranks on them assuming shell width and threading is the same the bottom bracket will be the exact same because it is dependent on the cranks.

If you are keeping the same cranks take out the old B.B. and measure that or look at the measurements printed on it and get one of that exact same size. Don't worry about what the internet back 18 years ago said, measure twice or have your shop measure and they can get you the correct B.B. (and also help install it if you don't have the skills or tools)