Dave,
As I understand your needs, you want a boat for YOU to RACE single-handed and your wife would like to FUNSAIL but NOT RACE.
You DO NOT plan to RACE double-handed.
You are 6'2", 210lbs and your wife is 5'8", 140lbs.
You live in Crystal Beach, FL, near St Pete.

I believe that an A Class would fit your needs very well.
Their dpn is 65.2, faster than any cat under 18 feet long.
Add a spinnaker and it drops to 62.496.
They are competetive with crews as heavy as 220lbs.
You could easily cary an extra 140lbs for an afternoon ride (she wouldn't even have to trim a jib:-).
Since the A Class only weighs 165lbs, it is easy for a single-hander to setup.
The A Class are very active in Florida. The Gulf Coast Championships will be held in Gulfport, FL next year.
There are many used boats for sale on the US A Class website .