It’s not rack mountable but I’ve been using Panamax M8AV-Pro. Has 4 constant powered receptivals and 4 that are switched via a 12v trigger. Best value that I can find. I use them in every pre-configured rack as aux power and to power the 110v fans at the top. I trigger it with a temperature sensor from Cool Components. Not sure what you need it for. Perhaps it will work for you too.

[Link: panamax.com]

Craig