cool.. Hope it works out!!..
200 gsm glass?.. I suspect you could drop to 100gsm if you wished. Although 200 will give greater scuff resistance...

If you wanted to be tricky you could use a combination of 100 & 200..
<img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />
But dont listen to me I enjoy mucking about in a shed too much.. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />