That's quite a project. It's ambitious, but it sounds like you know what you're getting yourself into. Please do keep us updated, as I am sure many of us who are less adventurous would like to live vicariously through your experiences.
As for the parts, here are a few threads that may help you:
2.7L engine:
FS: Complete 2.7L Boxster Engine
Parts Car:
Porsche 986 Parts
Parts Car:
FS: Parting 01 986 S Arctic Silver
Best of luck!