Wac makes a 2" can for cabinet and soffit installs.Most puck lights I've seen say not to install them in a ceiling. Of course GC's know everything and they love things like puck lights, handy boxes and pancakes. My suggestion is put in some 4/0 boxes and use these:
http://assets.sylvania.com/assets/Documents/LED279.7d853c5f-71b4-449a-8ff2-7c9ee94dabf5.pdf