I'd hate to push anyone away from the hobby, but large tank, large fish, and coral? You might get into more than you hope for. The biggest aspect of any large tank isn't the setting up of the tank, or the enjoyment of what's in the water, it's the amount of maintenance you need to do on the tank. For instance if I said, "what do you expect your water change schedule to be like" and you have a blank stare on your face, then definitely start reading up on keeping a tank, or start with something smaller... WAY smaller.
IMO, I had freshwater (crappy stuff) before salt, but I started with a 10g tank just to get the feel for what everything involved is the tank is about, protein skimmer, water movement, filtration, and yes, also realizing topping off evaporated water with salt water is not what you're supposed to do. Heck with Petco having their $1/gallon sale a few times a year, I'd wait pick up something like a 40g breeder, and keep some smaller fish with the corals to see if you can handle that, best case scenario is you pick it up, then get your 240, and the 40g is a hospital/QT/frag tank, worst case scenario, you're out $40 on a tank