I wouldn't use acrylic. Most big fish can easily scratch and gouge it leaving you with a horrible view. And with 6 feet tall you would need really thick glass, which would be really expensive. And the top would have to be braced very well.
Before you start make sure you want to do this. There are many build threads that never finish because people lose interest. Also make sure you can afford it. This will be in the quadruple digits at least.
Before you start make sure you want to do this. There are many build threads that never finish because people lose interest. Also make sure you can afford it. This will be in the quadruple digits at least.