Personally I'm not a fan of SSK's for the Boxster because they increase effort and notchiness too much for my taste. For about the same price as a genuine B&M shifter you can get the whole 997 stock shifter assembly. I'm not talking about the 997 short shifter assembly, just the regular one. It actually shortens the throw slightly over the 986 assembly and give a more positive shift feel. It is very similar to the 986 unit and drops right in place with no mods. I think Suncoast porsche has the best price on them. They were around $180 awhile back.
Looks like they've gone up a few bucks, but not bad for the whole assembly. Link below
http://www.****************************************************.com/product/997SCU.html?Category_Code=986Tran