I built a bracket similar to the one in the pic for my CB installation. I'm using a Cobra 75-WX radio that has everything in a single hand-held unit. There is a small power box that I mounted behind the passenger seat and the radio simply plugs into the box when I need to use it. The box also has the cable connection and you can by these boxes separately so you can put on ein another car and simply move the radio around as needed. I use the 12v ignition contriolled supply and ground wires from under the console (later C4's have these) to power the unit.
I was using a marine-type antenna but it never did work right. I went to a CB shop and had the SWR checked and it showed a ground fault!! I bought a K40 4' long top-loaded fiberglass whip with a small adjustable tip (typical car/truck antenna) d now it works great.
I used a 12' piece of RG-58 coax from the antenna to the radio to get the best SWR reading. Just coil any excess out of the way in someplace like the storage well behind one of the seats.
Some low-end CB radios do not do a very good job of filtering out noise from the car's electrical system. You can turn the squelch up on the radio, but that can hurt the ability of the radio to pick up a transmission at some distance. There are filters you can install on the power lead from the alternator, but a good clean install of the radio with good grounds will be the best bet.
One other thing I have found is that with the antenna in the back of the car near the power AM/FM radio antenna, transmitting will cause interference in the radio reception so it's best to have the car radio off when you use the CB.