I take a different approach. Rather than cutting the wires and driving into the case, I get a 20/24pin atx connector and plug it into the power supply. I connect plugs or termianals to the other end of my connector.Very flexible and minimum amount of work.
here's three I found earlier.
Quotehere's three I found earlier.those are even better: plug-n-play.Those atx power connectors are fairly difficult to find.
I use these PSU's for everything some of the current one's have more than 3 or 4 useable voltages i wanted to use one for my Arduino test lab/rig i figured a PSU would have to be stable for a motherboard to function correctly, Anyway i'm dusting of one now to use for a better power supply, just wondering besides proper fusing is their anything else i should be using to ensure i have clean/safe power for my projects ?