i have a system i built for similar purposes.. SQL 2005 for a sharepoint cluster - iometer is reporting about 110mb/s both read/write but when i run iozone (iozone -Razb c:\fileout.xls -f T:\myscsivoltest.lo1) things only look good on larger writes.
still fumbling through options in open-e. im pretty sure that everything else is tweaked and all that remains is the ietd.conf and IP options left to do.
PS - when benchmarking my disk locally Im getting 592mb/s read and 397mb/s write - enough to saturate 2 gig ethernet links.