Yeah, rentals in your size range will tell you what you'd like best. Sunfish is a great investment and a great one to learn on. Any boat that you can carry the sail
rig from your car and slip into the hull with no help will likely get more use. I used to carry one years ago on top of a Datsun 510. When you tire of it, you'll prob get your money back for moving up. Just don't get one that's waterlogged.
Here's a lot of boat for the money....similar to a sunfish. Maybe you can find something in your area.
http://norfolk.craigslist.org/boa/3356102199.html