Storz, you are correct that the hulls are the same. Sail area has been optimized to each boat (beam and righting moment differences).

Uni's are a ball. I setup and sail mine comfortably in most any wind at 185lbs. Standard size trailer too.

Flexibility wise, you can sloop rig a Uni or Uni rig a sloop without a lot of fuss as riggings are readily available. Certainly gives you options should you later pick up a crew. No need to change boats. All depends on where you see yourself going in the future.

Check with Mark at the Cathouse (located in Michigan). Last time I looked he had a couple of 5.5's on his website.

Sail fast, Tom G