Sounds like the F-boat is the ultimate answer. Since you only have to wait a few more years to get it, you don't want to spend a bundle on a new small cat now. So you need a used boat that is comfortable for two to "cruise" on, easy for one to race, and either has or can be adapted for spinnaker, and has a decent Portsmouth rating, and that is either cheap enough so that you can afford to keep it forever or will hold its value well enough so you can easily sell it when you move to the F-boat.

As far as I am concerned, it's the Hobie 18.