I used metal cast type (used in printing). I was lucky - an area
printer donated the old metal type. You might want to call around and
ask if any of the older print businesses have some? There is an
antique mall near here that has a booth that sells the type. You can
get it in various sizes. It last forever - I used in to stamp print
borders in various projects, too.
Here is a source in Canada that sells it:
http://www.donblack.ca/default.asp
You could email Don (Don at donblack.ca) and tell him what you want. I
don't know the difference between the different kinds listed at the
top. I am guessing that mine is hand set?
Maybe an old department store would have some old type used for making
signs? The department store I worked at (in 1980s) had a variety of
different sizes of type.
I know some schools have/had the old type too.... Check around. You
might get lucky. Now that everything is technology driven their old
type might be collecting dust