Ocelaris

Why don't you try using 1-way mirrors? Or some sort of mylar-mirror tinting product on one side of the glass. I would also reccomend Acrylic, as I think it's cheaper, more shatter resistant, easier to work with, and is a better insulater of heat (though you might want it to conduct heat). And you can easily drill acrylic, but glass requires some serious tools. I don't enjoy workin with glass. I think the only reason you use glass is if you have to work with high temps, like a lens for the light. You can always use reflective spraypaint on the back of the glass. I know when I lived in florida you could buy mylar that stuck to glass, it's supposed to reflect like 90% of the light, and I you can see through it very easily. I bet it's pretty cheap if you can find a commercial source, though you may have to buy alot. I think the car mirror tinting stuff is what I'd use. Ocelaris