Years ago, I watched the the guys at my local glass shop build a custom tank, I believe a 225. It was kind of a long, low profile. I'm pretty handy and can build just about anything in my shop but I wouldn't even attempt working with glass that thick, that size and that heavy!!! Getting it all in place and square with the glue seem looking good...........NO FRIGGIN' WAY Anything beyond a large nano, I wouldn't try. Maybe a little larger in acrylic.
Yunno..........My first SW tank had a slate bottom and stainless trim!! It worked great for about a year. The stainless held up but the slate began to leek Whatever that black stuff was they used as a sealant also crumbled away. My riser tubes and undergravel filter was so darn cool That was circa 1975!!
By the way if your going to attempt cutting glass over 13mm 1/2 think get a pro to cut it and bevel the edges for you less cuts when maintaing the tank rough cuts are sharp as razers