+ 1 for Musty suggestion- there is no point in getting a specific rod for unweighted pillies... BUT...
I wouldnt go anything below 10 foot for any casting type application esp from the ocean rocks, and I wouldnt go above 13 foot.
I would get a rod in either 5-8kg or 8-12kg and use a 7000 or bigger reel (for capacity) and load up with 30lb braid with mono backing.
Brands like Wilson, Silstar, Shimano and even UglyStiks are great casting rods in the longer versions, and make good spin rods aswell if you are so inclined to have a go @ chucking lures around...
Musty mentioned the "8 wrap snyder glass" rod... well I have one and they are designed to be used with Alvey's, they're heavy but cast a mile without a doubt and are tough as nails, matched to a 600 series Alvey they are hard to beat for toughness and relibaility... so easy to maintain... beat overheads hands down and outcasts most spin gear.
Good luck with the search
Anthony