I know i've probably said it a few times on the forum before, but anyone looking to tackle GT's from the shore should really have at least have one conventional reel setup. They are unbeatable for distance, and you can throw a very long running leader behind your bite leader. Just in case a fish gets you pinned under a ledge for a while, the long leader will allow you time to work the fish off the rocks.
The last two seasons my shoreline GT combo has been a PD Rockfist 115XTX Blank that i wrapped conventional matched with a Daiwa Hyperspeed both 30 and 40 and PE8. The spinning rod i throw is a United Comp 100XXH with a Stella18K with PE8 and PE10. Both rods dont even blink at fish in the 20kilo range, with the 100XXH being exceptionally merciless on fish.
I'm hunting for my 100lb GT from the rocks, and no doubt that these rods will handle the challenge!
Alex, Century blanks are phenomenal casting rods not really suited for GT's, but can bomb a plug to the horizon!