Morning all
I've installed a cb radio in the glovebox and wonder where would be the best place to get power from...ideally it would be a constant power regardless of key position...I have a discrete "through glass" antenna which looks like a cell phone antenna so the jags looks won't be compromised...pic to follow

 

I know you said you wanted constant power, but the cigarette lighter under the radio is really easy to get to... At least it was for my 5spd. I just pulled the shifter boot, then two screws and it was out. Then there are a couple little tabs on the back of the cigarette lighter that make it really easy to hook up stuff too. I used this for the remote turn on switch for my subwoofers so that they only turn on when the key is on.