If you use 5V you should mount shark fins and chimneys in both gabinet sides to help cooling. That may cause turbulence in undesired places so it would be better to add sidepods with vortex generators to let air run smooth arround the mouse, keyboard and monitor. With all that you´ll get a good performance from your PC!
BTW, remember to use helmet, seatbelt and HANS (Hand Arthritis-prevention New System):
"You need great passion, because everything you do with great pleasure, you do well." -Juan Manuel Fangio
"I have no idols. I admire work, dedication and competence." -Ayrton Senna