I've debated a few different vintage sets but my current project is completing sets back to 1972. I've gotten really close on my 82-84 sets thanks to a member here. Once those are done, I will move on to 80-81...hopefully by the end of this year.
I do have 10-12 1960 Fleer cards and I may start working on that set as well. After that, I think '66 Topps is a likely candidate because I have a bunch of those (though not necessarily in great shape) already.
And I really dont think a vintage section would take anything away from sale of 'new' product. I think vintage collectors are probably more the set builder type and really it's cheap to build modern sets compared to vintage, no reason one can't do both.