I'm using a JNI FC64-1063 here myself, on an E4000, to talk to a CLARiiON
FC5500 array, and it seems to be working very well. Of course, both the
JNI card and the SP boards in the DPE itself seem to be using the "Tachyon"
FC controller chips, which probably helps.
I did try the EMC version of the card a week or two ago, and it made
the machine crap out on startup. Then again, the board had some physical
damage and I'm getting a replacement. (got the non-EMC one as a
just-in-case "Plan B", because it was cheap, and it seems to be working
just fine)

-Derek