One thing I'll be looking is a 120mm adapter for the pair of 80mm fans used here. When you put your hand next to one there's hardly any air movement felt. With the case in an enclosed area a pair of 120s would help there. The case for the next build will probably be an air conditioned model not water cooled.
In addition to adding a front case fan there are hard drive cooling kits available. Just how great they work is another matter. This is one I am currently considering with the two identical drives here. As a plus I added a second 3rd party cpu cooler with a 92mm fan sitting in the middle of the Zalman brand heat tubed setup there. The air flow helps keep the video card temps down as well as getting air moving. It's a nice looking case. But if I don't get an air conditioned model at least the next will have 120mm instead of 80mm fan openings.