You did say "Professional looking" and this would certainly fit the bill. http://www.protocase.com/products/index.php?e=RackmountGoogling "rackmount project box" turns up additional results.If you want to do it yourself then you want a "sheet metal nibbler". A manual nibbler will run ~$10 or pneumatic ~$40. Beyond that you would need to move to a milling machine or plasma cutter process. If your total case is light enough you might be able to replace the metal front with an plastic front (ABS or acrylic, etc.) which Pololu.com could cut for you.Out of curiosity, what are you monitoring? Temperatures or power strips?
I am mainly looking at Monitoring Temperature, Humidity but would like to get into Water Leak Detection as well