Window a/c mod is the way to go, if your room allows for it
its really nothing special, some dryer duct, some duct tape, and thats pretty much it depending upon how much modding you want to do.
Like badtaylor said your cooling is limited by ambient air temps. Solution is to cool the air surrounding your pc case, or inject the cool air directly into the case.
edit. You also need a window a/c unit...