what exactly do you want us to modify? i mean, what needs to be fixed or modified in your case cooling layout that you want to improve? Are you trying to make the ram or the cpu or the vid card cooler? If it's for the cpu, why not make a blowhole for your processor? There are a bunch of plans out on the net. Also, try taping up or putting caulk or something like that on all of the small gaps and holes in your case so that you have a more closed environment. Also, be sure to use that air in a can (not like the stuff from Spaceballs) to blow out all the dust because when that stuff starts to accumulate, your temps start going up.
Intake, intake, intake...you say there is no hole in the front for an intake fan, so cut one! Use a dremel for the open air do the measurements (twice), use a drill for the screws. Aside from that, you could also add a side fan that blow directly onto your gpu. This would require cutting into the side panel of your case and adding a fan there.
If you don't feel the desire to cut, then I would suggest a new case before you start overclocking. Check out <A HREF="http://www.newegg.com" target="_new">newegg</A> and look at the cheiftech cases there.
Disclaimer: Please use all the appropriate safety equipment when attempting this, and make sure you take you computer OUT of the case before cutting.