LSVT. Interesting that u looked at a Cayman first which is not a convertible and then looked at a Boxster S. With PDK I believe it is not manual per se.
Would u rather drive a manual trans. or does the PDK tech. do it for u? If I were u I would feel like a kid in a candy store especially if I had the $$$$ to buy something new. Take your time looking because if you are willing to spend big $$$$ you will have many options. My concern is if I were u I would make the wrong decision and regret it later! Enjoy!