The current Red Hat qlogic driver doesn't support most of the adjustable parameters. However, the one you can download from qlogic does. Red Hat will include this driver in its next release (beta in about a week, production in mid-September). In addition, Red Hat will support multipathing to at least same level as what SuSe supports today: http://portal.suse.com/sdb/en/2005/04/sles_multipathing.html
Red Hat is just a bit behind, but if you really need this in production, I'd suggest you contact your support and/or sales rep to ask them to support you with the beta release. How much luck you'll have, I don't know.
Thanks, -Alan