How many fans can you have total in the case?
Generaly a good idea is to have the front fans (if you have any) blowing in, and the window and rear fan blowing out. Its kinda like....well, its just good air circulation. Make a drawing. Point out where the air will be comming in, and where its going out, and figure out the best way to set up your fans.
Also, think about using round cables (IDE and Floppy, naturaly) if you already are not. Round cables present less air resistance, as compared to old school ribbon cables, which are rather big and bulky, and just plain out ugly anyhow!
If moddings an option, think about a blowhole. Put a fan there, and make it suck air out. That would work wonderfuly.