Good luck on the radio search perhaps some can chime in with firsthand experiences with the kg-1000g.
For the magnet, that's a good (and creative) idea as well. The other consideration with a mag mount is cable routing. While I've absolutely done it (mostly ran 2 till I moved one antenna to a fender mount), it does eventually take a toll on the paint at both the mount and wherever the cable runs on the body. In my case that was mostly where the cable tucked under the edge of the door seal at the top.
On routing, I had a seal i could tuck under, follow the rear edge of the passenger door seal down, and loop up and in at the bottom (single cab compact truck, rarely had passengers). Current crew cab, the seals are tighter and don't hold the cable well, and all 4 doors get used regularly, so mag mounts are less optimal and mostly saved for when I'm running solo...have a comet 2x4sr on a fender mount for regular use.