On the starboard side I have a Dbot5 Axl double surf rack. If I were searching now, I'd look at the Nice Rack double surf rack on onlyinboards, as well as the Krypt Dominion Double Surf Rack. Of course, that's assuming you'd be looking for a double surf rack.
"I have seen one person that actually cut out the middle prong of the stock rack and it actually did a nice job as a surfboard rack." Make it 2, the upper rack on the port side was a double wakeboard rack that I cut the center fork out of. Now I store a CWB Razr and Broadcast together in the rack.
What boards are you looking to store?