I use a carp rod for pier and beach, a properly loaded fixed spool will cast a fair way with a weight of about 1-2 oz. Keep the rig simple, a single hook paternoster or two hooks sometimes and it fishes satisfactorily in my mind. It can change to a float as well. I think if a carp rod can handle 20lb+ carp then can handle much of what I might catch in the sea however, hauling a big fish up a jetty or pier wall can be difficult as theartist said, possibly better to hand line it but have gloves handy otherwise the line will cut in too much, still not an easy thing to do though. But, what am I likely to catch , nothing much over 5lb. Flatfish, mackerel and the odd bass but, it would be rare to get one over 10lb but it would give you a bit too much to do on a carp rod from a pier but most are sort of 2lb -6lb.
For a strong current and heavy seas you need heavier though, stiffer rod and more weight, a lot depends on where your fishing. I bought one of those cheapish combos for a beginner friend of mine last year, £35, the rod was not bad and the reel came fully loaded, I fished with it myself and I thought it was pretty good for general beach and pier work, casts a 4oz weight pretty good.
It mostly comes down to what weight you need to use to hold the bottom, once you know that -that should guide you as to what rod would be best.
It is difficult to advise without knowing what the currents are like and the general size of fish you expect to catch but I hope this helps a bit.