Window inserts

A friend of mine just bought an older house with a
a very sturdy structure. All of the windows and doors are very deeply (3 &
4 inches) set. He would
like to have several windows done with stained glass. The exterior windows
are very well set and
are weatherproof. Instead of replacing the existing windows, I have
suggested mounting his stained
glass inside.

I have done this in the past with 18" octagonal windows with breathing holes
to prevent moisture
and mounted so that they can be removed for any
cleaning as needed. His entrance doorway has a
a very large glass, with two sidelights and a full
width fan at the top.

Does anyone see any pitfalls in doing interior glass
installed against a wooden stop. Also, should this
be all lead came or a combination of lead and copper foil? Thanks for any
ideas or suggestions.

Hal