madmodz, my part number is the same as the one that Meir posted above: 997 605 115 00 and it came off a 2.7 Cayman
this is a really long read but it's how i got interested in ben's product. in it, TRK and others share that 996/997.1/987 throttle bodies will all work. if you go 987, you can use either s or non s. just be mindful that if you're on ebay and you see "boxster throttle body" that the number starts with a 997 and not 986!
http://986forum.com/forums/general-discussions/31693-maf-throttle-body-diameter.html
hope that helps! it took me a bit of time to figure out the right ones too, and you're right, there are quite a few sellers out there either misrepresenting or not knowing what they have.