Some Suggestions...
Wes,
I would suggest you consider using a product called "Sculpt or Coat" to create the smooth finish for your beak (
www.sculpturalarts.com). I've used it before to create beaks with great success. It's a white cream product you rub over the foam shape - it will fill in the holes and provide a smooth finished surface. I believe it's the solution you're looking for. If you mix it half in half with joint compound, the finish will dry rock hard - you can even sand it! Finish it by painting it the color you want. If you want a shiny finish, simply apply one final coat of Sculpt or Coat over the paint and it will dry to a clear gloss shine.
As to creating the shape of the beak, there may be an easier way, but I'm happy to share what worked for me:
I started by cutting the mouth plates out of a plastic called "styrene." You can get it at local sign shops - it comes in several thicknesses. I used some a bit thicker than, say, the thickness of a CD. (The styrene won't hold the bend of the beak without some help, but it does provide a good, bendable mouthplate.)
To hold the bend, I used a product called "chloroplast." That's another sign shop product - a heavy duty version of cardboard made completely of plastic - VERY sturdy.
I cut a profile view of the shape of the bend out of the chloroplast and used epoxy to glue it to the styrene mouthplate. Of course the chloroplast was glued to the side of the mouthplate that would be out of sight, covered by foam. This process was repeated for the lower mouthplate as well. That created the permanent bend of the beak.
That puppet was built as a commission a year or two ago, and he seemed very pleased with the result. Using those two products (styrene and chloroplast) as the skeleton for the beak provided a feather-light manipulation, even though the beak was quite long.
Hope this makes sense and is helpful - good luck!