construction grade materials. do not use osb like i did! use plywood and 2x4's cause they are mass produced and cheap.
stand: stud walls all the way. with cross braces if needed. remember whole houses ar built on these. my stand could hold three times what it is now.
i used glass because i already had it, it is 6mm and tempered. it works but most willreccomend thicker. acrylic is good too.
i used fiberglass resin, it's like a 2 part epoxy and sets up very hard yet brittle and flexes well if the matting is used. when i do this agan i will use plastic home panels or abs sheets to seeal with. they ar only $30 or so and are much easier and more durable.
list:
2x4's (stand, tank wall bracing etc.)
plywood, this is where you can't skimp out and buy osb or wafer board, thicker is better but you can cut down on thickness with extra bracing.
sealant, fiberglass resin, epoxy, or plastic sheeting of some sort
thats pretty much the basics, just add what you want to make the tank yours.
check out the diy forum, there are tons of tanks and tons of different ways of doing it. good luck!