Two years ago I had none, but now I have a '70 D-25 (flat back), and '73 D-35 (a less blingy D-40) and a '74 D-25 (arch back). I went this way because I like the old wood. I find the '74 arch back has a more focused tone (less resonant) and it plays well with a K&K pure mini. It is also the heaviest of the bunch at 5lbs-6oz. It seems loudest, but my decibel meter says they are all about the same. If you like a lighter guitar, go for a '70-'73 flat back D-25 or D-35. If 5lbs4oz-5lbs9oz is ok, then any D-25 or D-35 made in 1974-1990s should do it for you. And DV-52 and D-4 might fit the bill too.
Option 1, get one from Guitar Center, have it shipped to a local store and get 3-45 days to have a luthier check it out (vintage is supposed to be 3 days only, but most times, old D-25s are just listed as "used" so you get 45 days. Their prices are pretty fair most of the time. I generally call a shop and talk to a tech. For the '74, the tech was like "get this guitar!" and he was right. For two others, I have had them warn me off.
Option 2, ask the seller for the low-E action at the 12th fret (dist from top of 12th fret to bottom of the string) and also the distance between the low E and the top of the guitar at the bridge. If the action is less than 6/64" and the string is > 0.4" above the top at the bridge, you probably wont need a reset for some time (but might eventually). If the action is 5/64" and the height > 0.40", you are really GTG. This string height is better than the saddle height as bridges often got sanded down to avoid a reset, causing all sorts of problems.