Ok Dude, I'm not speaking from experience here, but I heard that the underdrive pulley for the crank is a pain in the butt to install, and you pretty much need to pull the engine to get it on. I've also heard that that's the only pulley with which you would see actual gains, like 2 hp at most, on the dyno, thats with the water pump pulley and alternator too. I wouldn't spend my time pulling the engine just for the pulleys, I'd put that money toward a catback, and wait for a time when you're doing some major engine work to slap on those pulleys. They do look damn good though...
Whatever you want though, its your car.