J/24 might be a good idea. Is a known commodity (unlike some others)and is widely available. It is a lot of boat, and one in your price range would likely be somewhat tired, but it would be worth fixing up if it needed some. They perform well, (especially compared to a Nutshell pram, which you could use as a tender),and they are big enough to take a bunch of people out with you, or go places over the weekend, or race, depending on what you want to do. A lot depends on where you are, the local fleets (for possible resale later) and what you want to do.