Doable, but be prepared for a LOT of work and a LOT of patience. I read everything I could about this install, read up on the job in pelican's 101projects book, read up on all the advice from several different Boxster forums, and bought all the right parts. Took 7.5 hours. And, yesterday it rained hard and a lot. Didn't see a single leak. I guess I got it all back together successfully! But, I do have a slight wind noise from the passenger side. Sort of a very quiet whistling sound. Just sitting in the driver's seat, the seal at the top of the window doesn't quite look straight. I'll readjust it this weekend and I'm sure that wind noise will go away.
Rag Top Replacement
I checked with a local upholstery shop that specializes in replacing tops. They wanted $500 to do the install if I were to bring them a top. If you're not sure about doing the job yourself, I suppose $500 is cheap insurance to insure it gets done right. And, you don't have to spend a whole day trying to figure it all out.