i have the nf4 sli-dr expert and i love it. alot of overclcking utilities in the bios. the only i dont like about it is with my 7800gtx the card over overlaps the chipset fan its so long. not major but just something i noticed.
I would have to 3rd the Ultra-D. Its relitively cheap, many options on it and it can be modded to SLI. My 7800GT also overlaps the chipset fan but that hasnt done anything, inst a problem at all.