a couple questions on a fishtank build

[fishingfool]

So i was thinking of building an oversized fishtank for ether a golaith tiger fish or silver arowana I'm think like 300+ gallons anyone know how thick the glass should be and if i should build it incased in plywood and 2x4s with viewing wondows to brace the corners on such a large tank and if there is anyone with these fish an idea of the gallons required for these fish and if the water needs to be running would be nice also