I just purchased a 2000 Boxster S four months ago and had three axle boots replaced at BHR. Very reasonable. I haven't any experience with Imagine but everything I hear is that they're high end—who knows? I'm thinking about having the oil changed at the dealer. They have a pretty sweet deal—$59.95 including M1 oil and OEM filter. PO had work done there.
http://www.bobhindsonracinginc.com
http://www.aristocratporsche.com/Specials-Service.aspx