Jim, I was wondering how you knew I had a 5820k, but I guess most Envy 850's have them.  I considered the 5930k, but it seemed the boost/$ wasn't a good deal right now.  It seems that I might be able to go to a 5960k on the future once they become more affordable. 
 
It will just be the sound card and the video card, there are no other open slots.
 
I decided to take a chance on the PCIe 424, it's less than a new interface, and I don't have to pull the 2408 and re-wire the connections (worth ~$100 in my book). 
 
The card arrives tomorrow, how do I tell if there are shared resources in the device manager?
 
Thanks to all (especially Jim), I'll let you know how I get on with the PCIe 424.

You can look in Device Manager and see if anything is sharing an IRQ with the PCIe 424.
The PCIe 424 is an excellent performer.

Rats.  It looks like they ARE sharing an IRQ - 16.  Better to leave alone, or try changing?  Changing is currently blocked (by ACPI?), but it seems many low values are untaken. 

Some devices share just fine... 
If all is well... there's no need to worry.