I've got two home-build Halloween props that currently run from multiple battery packs. I want to switch this to a single wall wart. Here's what I need to power: 1 arduino, 2 Cowlacious audio boards, and 1 Cowlacious Scary Terry servo board in the one prop, and one servo board in the other. 9 volts is a fine input voltage for the power input on each, and ideally I've love to use the barrel connectors on each, since it gives a nice firm connection even when I jostle the setup.
What do I need to look for in a wall wart?
Can I just rig up wires with barrel connectors on one end in parallel off the wall wart?