Overhead works good, just take a piece of metal bar, bend, drill two (or three) holes to match the rearview, remove mirror, put bar in place and reinstall mirror, and voila, CB overhead mount. Then run the wires behind the windshield gasket and down the a-pillar to power. I used mine like that on my gen I's for two trucks, and liked it because the speaker was underneath on my unit, and I could hear it a lot better.

On my genII I have the cobra that fits a din panel, and mounted below my head unit (Front-mounted speaker). That works good too.

1991 HZJ77, 1999 KZJ90, 1999 UZJ100, 1992 M101CDN2
https://www.thegearheadproject.com/category/jdm-journeys/