Don't start off a tank with a born killer like that. In over your head buddy.
If the dimensions are at least 3' long and 1' deep then go for an Oscar, but only if you'll be able to upgrade it to a larger tank once it's about 7-8'. Oscars are pretty good monsters for starters. They eat a ton and will bug the living crap out of you, but have awesome personalities. It's like the training wheels for the bigger badder fish out there.
I wish I could get rid of mine but I got attached to the little punk and it'd kill me now lol
Just be ready for a TON of food going into the tank, lots of cleaning, and head aches all the time cus he did something to tick you off (mine likes to "redecorate" and break stuff)