Buying vintage can come with a few problems. Unless you really know what you’re buying I would buy new. Vintage can mean more regular servicing aswell.
I can guarantee you’ll want more than one as you’ll catch the bug.
39mm is an ok size, but I’d try a 42mm aswell. That seems to be about the norm these days. Depends on wrist size aswell.
You don’t give a budget but at prices of around a grand, I’d look at Glycine, Nomos and Fortis. You get alot of watch for the cash. I’d personally go for the Nomos.