Dive with Martin is a great choice, we have used them for several years, request Orlando or David if you can.
La Ceiba used was our Cozumel home for years, it has a great location and a very good staff you should enjoy yourselves.
They used to have pretty good shore diving right out in front, for Coz. "Airplane flats" is the site, there were remnants of a place sunk for a movie out in front of the hotel just outside of the swim area. I don't know if any of it is left post Wilma, but the dive is a very shallow slope from shore to about 30-40' small coral heads and shelves.
Most of the shore diving was pretty scraped up during the hurricane. most of the seafans and soft corals and sponges were distroyed or badly damaged.
Having said that, we did some shore dives in May and there was plenty of sealife to be seen. sure you had to poke arround the rocks some to find some fo it, but it was there in abundance.
Take a day to drive arround the island, stop at "Coconuts" over on the Caribbean side, have a margarita (warning VERY strong!) and ask to see the "family albums"
there are several small beach bar/restaurants along the way, but I think Cocnuts is worth the trip for the view alone, it sits on a bluff, probably Coz's highest natural elevation, over looking the Caribbean Sea, very cool!