Pete C wrote:
Stephen Gower wrote:

* Where should I go and what should I ask for to get a piece of
heat-proof, slightly tinted glass, roughly 400mm x 160mm?

You want borosilicate glass (Pyrex) or ceramic glass (as used in
ceramic hobs), a search [...] should give a few leads such as:

http://www.skan.co.uk/heat.htm

I had already contacted Skan before you sent this, but thanks for
the reply! They were incredibly helpful, although I did have a 2
hour round trip since neither of us was willing to entrust the
glass to a courier.

I am now the proud owner of a piece of Robax (ceramic glass). I
just need to design the specifics of the stainless steel frame, and
my fire surround will be well on its way.
--
Selah