I'm considering an old 3 hander, basic Seamaster, I believe, probably from the 60's, or possibly modern of similar design.

There appear to be so many variants that I'm not sure what's what!

I suppose I'm looking for something like the pic below, but ideally as large as possible; most appear to be 34mm; are there any larger ones in this style?

Is there a good online resource for the different models/specs?

Many thanks for any help.