I would not use a fixed spool myself in Kelp, even the best makes do not have the cranking power of a decent multiplier...plus they are not really designed to cope with lines of 30lb plus, which I use to combat the rubbing effects of the rocks on the line.
For rock fishing I use a Penn 535 Multiplier, tough as old boots, it has centrifugal brakes, and it will really pay off if you take the time develop multiplier casting skills.. if you are a bit unsure, there will no doubt be a casting instructor in your area who would be able to help, you will not be casting so far if you are rock fishing,so you wont need tournement casting skills, ask in your local tackle shop, they usually are very helpful, or check out one of the monthly sea angling magazines, they usually have casting instructor lists.
Oh, and a rod designed for a fixed spool reel would not be suitable for a multiplier, it will have the wrong ring spacings .
Costly business this sea fishing lark..
Tight lines.
Dave.