Hmm... I'd look for something that is small enough to trailer. That would cut down on the storage costs and make working on it a lot simpler, since you can often do a lot of work on the boat while it is sitting on the trailer...I know I do... As long as the hull, deck and rigging are sound, it sounds like you're game. I'd add that the centerboard or swing keel, since many boats in this size range will have one, should also be sound.
A West Wight Potter 19 or Montgomery 17 might be good choices to look at. The Hen series of pocket cruisers might also be a good starting place. S2, Catalina, Hunter, and Beneteau all make <28' trailerables that might work well.
Personally, I would recommend you keep the boat in a marina, on a mooring, as that makes going out for a short afternoon or evening sail much easier than if you have to launch, rig, de-rig and haul the boat each time.

If not in the water, keeping it a marina and having it pre-rigged on the trailer ready to launch would be the next best alternative.
I'd recommend you read the
Boat Inspection Trip Tips thread I started, as it will help you determine whether any boats you look at are even worth going forward on. Start looking on Craigslist and walking through marina yards...you may be surprised at what you find.
Good luck and keep us posted.