I have had good luck running lights off of a CPU power supply. I run LEDs tho so they dont draw a lot of amps. Here is basically what I went off of but not to the extreme they did. I just linked the Green/Ground, and used the cables coming off the supply instead of adding the binding posts. It may not be as clean as the write up, but it gets the job done and it is hidden anyways. The next couple I build will be basically his set up with binding posts but I will only have one for 12V and ground. Oh, and in place of a resistor you can use a 3357 or 1157 bulb. They draw the same load with both filaments lit up as the resistor does. I used the bulb idea.
How to Convert a Computer ATX Power Supply to a Lab Power Supply - wikiHow
Here is the basic set up of what I run currently off one supply, there will be a second mini bar added, and a few more heads. It can definitely handle the load without a problem and stays very cool running all day long. I am running an SVP 20" Aerostar 8 Head M-Tech Bar, LED
HAW's, 2 Sound-Off LED3's, and 2 Whelen OS Lights.