Hmm. Not sure where you can have a clam bake. I know there's a place called Merri-Makers, which (I believe) is in Sea Bright, which is right on the beach. There are quaint B and B's in Ocean Grove, which is just down the road from Sea Bright, if you're looking for places for the guests to stay. There's also the Sheraton in Eatontown which isn't too far from the beach, if you're looking for a larger hotel.
I've been to a wedding at McLoone's which is in Sea Bright....it's on the Navesink (?) river, so it has nice sunset views. The food is excellent and so was the service. The ceremony took place at the pavilion in Ocean Grove...it's a small, open-air place with benches, right on the beach. Our friends then had their photos taken on the beach.
I just got married this past November. Maybe try http://www.theknot.com and go to the northern NJ message boards (under the "talk" forum)....you'll find a lot of bride-to-be's there with some great advice about vendors and places and all sorts of wedding-related stuff. I got a lot of great tips from the ladies on there!
Good luck and happy planning!
S1 :)