As Blake said custom CURVED glass you will be spending big $$$$
http://www.spectemp.com/Default.htm
Company that does this somewhat close to you that does custom bent temp.
As far as cutting down or sanding down existing tempered glass, not gonna happen. You will be lucking to sand down a 1/6" to 1/8" before having the lite break. Flat glass is not a problem, as soon as you talk bent or curved glass, its a whole nother animal.