What I did for shutdown / wake on my A1U cab that I modded with a mini PC is I have the PC and A1U power supply (used for the LVDS board and marquee) both plugged into this wireless wall outlet, and the on/off switch for that is laying on top of the cabinet, right behind the marquee and out of site, secured with a bit of velcro tape.

I use BigBox as my front end, and it allows me to choose either Shutdown or Sleep. Not wanting to go though full startups all the time, I usually choose Sleep, so in Windows I turned on hybrid-sleep, which basically means when it's told to sleep, it actually hibernates.

After I put the PC to 'sleep' or I do a shutdown, I then power off everything using the wireless switch so that I don't have the LVDS and marquee going all the time. To wake the PC up, I have the PC's BIOS set to 'wake on power' (or whatever it's called)... basically, next time I turn on the wireless switch, the PC wakes up (or boots if I had done a shutdown) when it senses the power being sent it it again.