Re: 986 Boxster S engine
There are a bazillion mufflers for your car. OK, I'm exaggerating. The most popular are the Porsche Sports Exhaust (PSE), Dansk pressed, Dansk saussage (=Fabspeed), and GHLs. Other good ones include Ruf and Remus. There are still others like B&B and Borla, but nobody seems to like them. Of the first ones listed, the major differences are between sound level (and associated resonance). There are also major differences among price. To me, the Dansk ones unless coupled with other mods are too tame. The GHL is too wild for me. The Remus is in between. You can safely ignore any manufacturer claims for HP or weight savings as they are pure lies coming from marketing or finance.
If you have a 3.2, I don't think a 3.4L is a worthwhile upgrade (+6% displacement?). A 3.6 is maybe. I think there is a good supply of 2.7L folks keeping an eye out for a 3.2L at a good price. Don't be fooled into believing you'll get the HP spec'ed for an engine when installed in a 911 when the same engine is installed in a Boxster. There are major differences in intake/exhaust routing. That is also where the bulk of the 987 performance came from.