Hey mate,
In my opinion, it really depends on your beach fishing style.
Personally, I'm a lazy ass. If I go beach fishing, All i want to do is stick the rod down on the holder and relax with a cold one. In my case, I would opt for a Baitrunner. No need for tightening up drag when you hook up, just lock the handle. I use a Baitrunner 12000D, quite big but an 8000D would do the job.
If you're planning on spinning on the surf as well, as everyone mentioned a 6000/8000 size reel would do the job quite well.
Remember with Beach fishing, be prepared to clean your reel after use or have fun using a cement mixer the next time you go out (Sand with Saltwater spray doesn't go well with reels).
Again, depends if you're planning to use the reel for multiple purposes.
Cheers
Mark