Randall, try
www.leatherseats.com . I bought a set of seat covers for a nissan maxima from them and they were top quality. Very reasonable for "full leather". I checked there site and didnt see a set for the boxster but they can make anything you request. They also have an installation kit. The seats seem pretty simple to install on our cars so it may be worth the effort. If your going to be needing new padding an upholsterer will likely be needed. Good luck w/ your new project. I will be happy to see you get all of your cosmetics done so you can start that engine transplant project.