I personally like this article. Had some great info but was a gallon or 2 larger then you planned
Building a 1700 gallon Shark Tank
I have seen Bambo sharks in small 300 gallon tanks but they done look right. A standard 300g is approx 130 x 24 x 25 Tall. Not a lot of turning room especially as the shark grows. I think a more square tank might be better but still cramped (310 Square 48 x 48 x 31 Tall) You will have little room for rock and such.