Sorry, I forgot about that Jeff.
I suppose I could use the HS material instead, it was just that my friend heard about my project and gave me all kinds of CPU heatsinks. Using yours would save a lot of epoxying!
As far as the shroud goes, probably not (but thanks). Like I said in a previous post, I will likely mount the heatsink fins-side-down in a tunnel type of arragement, and mount the fans so they are an intake and exhaust setup.