Hi there
Big tanks are a lot of fun/hastle but you'll love it.
I have a 175 gl. full of Barbs.
You'll need 2 heater, each big enough to heat the tank, much more even heat.
Two Rena canister filters, that way you can clean one at a time.
Depending on how much water circulation you want, you might look at getting a couple of submersible pumps to push the water around the tank.
Make darn sure you have a good stand, NO short cuts here!
This is all for a freshwater tank, salt is for others to comment on.
I would recommend going freshwater till you learn an awful lot about fish husbandry.
$.02