It's hard to tell from the pictures you included (on my phone), is there any way to remove the air from the cabinet behind it or below it? Including fans which circulate but don't remove the warm air isn't going to help very much. From the looks of it you might be able to put a mesh or screen in the toe kicks? Ideall, if you could draw air in from below the cabinet via the toe kicks and then push it out the back it would be best.
I put my AV cabinet inset into a closet wall so that it's flush with the wall, this way I can go into the room behind the rack and cable things. I included fans at the top and bottom of the cabinet (39" tall) and the back door can be opened to access gear. The shelves have about 3" between them and the back door so there is quite a bit of airflow within the cabinet.
For the fans I found some cheap computer fans from memory express that are thermal controlled with sensors which I can place near the equipment.
http://www.memoryexpress.com/Products/MX22913
I used an old 12 volt DC power supply for an external hard drive I think, 5 minutes of stripping/soldering and I had a decent, cheap, thermal controlled fan system. They are almost silent at the lowest speed, and very quiet when ramped up.
I will see if I can dig up pictures if anyone is interested.