Better find out where the leak is first. No sense spending extra $$$ if you don't have to. Easiest way to check if it's the IC is to remove the Y-pipe and look for residue. If there's no slime all over everything, you're okay. If you see slime, get the wallet ready.

As for the belt, it runs every accessory. If it breaks/pops off, you lose everything but engine power. Been there too!