Need Some Advice

Hi everyone im new on the site, I've kept fish for many years but now i want to take it to the MONSTER level. Im thinking about building my own tank aswell as sump, The tank im planning will be 96in long and roughly 24in tall and wide and made from acrylic, i have Pacu, Silver Dollars, Silver Sharks and a fire eel in a grow out tank to add to the new tank in due time, i was also gonna get myself a aro and some kinda bottom dwellers (suggestions???) i guess my main questions are:

how thick should my acrylic be?
How big should my sump be?
What do you guys think about my stocking plans?

but any input or improvemnts on my ideas would be great

thanks Mac