You well say that you can't afford new, or nearly new, so that shuts you down for the Formula boats. You also want performance in a used boat, that sends you to the NACRA/Performance Cat brand lines.

You can find a used NACRA for less than $5K and will be competitive, esp. with a new sail. My suggestions: 5.5 or 5.8 for your weight and strength. Prindle 19 is also not a bad choice, but as you get above 18ft, the boats are exponentially more of a hand-ful.

What's in YOUR area? Try 'em! See what you like from firsthand knowledge...