We have a desktop training system mounted on a 2' x 4' piece of plywood.
It has the cRio, the full electrical distribution system, pneumatics, window motors connected to the Jaguars' etc.
It is powered by an Astron RS-12A power supply. It works find but I'd suggest something like an RS-35 or so.
As Al pointed out, do NOT screw around with electricity if you are not sure what you are doing.
The Astron supply is a rugged supply, UL approved and provides a reliable supply for what you are doing.
Go
here and select 'DC Power' on the product type pulldown selector on the left menu bar.