I've built large acrylic cases before, but if you haven't, it would be in your best interests to go to a glass company and see how much they would charge...acrylic is finicky to work with, and expensive, so you would want to have someone build it with a fair amount of experience.
Check out some articles online about building tanks using acrylic, if you decide to make it yourself, they can provide you with some good tips. I would recommend building a couple of smaller cases out of Lucite or Plexiglass, both of which are available at your local home supply store (Lowes, Home Despot,etc) to get your "feet wet". You can use a variety of clear glues, AC works well, but watch the runs!
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