Looking for new small boat.
If you are looking for a fast sailing boat to continue to build your small boat sailing skills, you might try the 505. They are not extremely popular in North America but they are an Olympic sailing class boat. I have crued on this boat several times with a very accomplished sailor and friend and in my humble opinion, you will be hard pressed to find a more exciting boat to sail. Keep in mind this boat requires a single crew member who will be out on a wire and controlling the gib or spinaker while the skipper steers and controls the main.
For even more exicetement (but far tippier boat) you can try the 490 skiff. Both the skipper and crew are out on the wire. There is a whole category of skiffs to choose from which can carry up to 3 crew members. But those are pretty fast and demanding boats that require a lot of skill and teamwork.
Catamarans, like a hobie 16,18, or 21 are another good choice and are far more stable and easy to sail. All are easily trailerable by most cars.
Hunter makes a 14, 17 and 21 foot trailerable boat. The 21 is especially nice and quite spacious. It can easily handle a crew of 4 or 5 (especially if 2 are kids) for a day. Don''t let the size fool you - it is very easy to pull with an average sized automobile. It is not a racing boat but has quite a nice sail area so I think it moves along fairly smartly. It is also very stable and friendly to sail. Pretty too.