I don't know much about CK suits other than they're not quality suits. It's probably just the lack of nice styling that makes it look conservative. I was using the term conservative as a nicer term to use than what I meant... I meant that suit looks boring. Don't get too interested in slim-cut when looking at department store suits. Most of the time, they really aren't cut slim.
Regardless, taking the suit to a tailor will help. Next time you want to get a suit, I suggest going up a level in buying a suit. In the quality range of department store CK, you're not going to ever be happy with what you get.
You can get a decent suit for around 500 bucks. Save up, you'll be happier. Suit Supply, eHaberdasher's Benjamin suit, even Brooks Brothers 1818 on sale. Or, if you make it to NYC, Uniqlo is also quite nice fitting for slim guys. Heck, even H&M sometimes have suits that are inexpensive that fit somewhat decent for a slim guy like you.
Anyway, take your time. Browse the forum. Take a look at what people are wearing here (see What Are You Wearing Right Now thread). Not everyone dresses perfect, but there are always some interesting ideas. There are also a few really fantastic dressers here. Most of the time their items are made completely custom though, which is going to cost a lot, but can be incredibly rewarding if you like this kind of stuff.
edit: I take it back, the suit is somewhat slim fitting. It just needs to be altered.