I used to use the Alon mount but I switched to the Super Duty Fender mount. I have the power wired to the PS auxilary port on the Bezel. And for the ground I used a bolt underneath the cup holders. The seatbelt bolt probably is just as good though. My signal still isn't that great though. Need to figure out how to make it better. So I'm watching this thread haha
depends more where you mount the antenna than how big it is (though bigger certainly helps! the more antenna above the roofline the better. best place really is the center of your roof, get a nice reflecting surface.
Something I would like to add is that a GOOD antenna is important, if your using a cheep Firestick your not going to get much range, but a good antenna such as a Wilson will get you out much better, I have had better luck with cheep 102 inch METAL whips then I have any fire stick, how ever they dont call them "whips" for no reason lol. I personally have a Wilson 2000 Trucker that is about 4ft long but works much better then any Fire stick or fire stick like antenna I have used. I havnt used it in 5 or 6 years because I havent had a CB in my truck but I have been thinking about putting one back in and If I do that Wilson 2000 will be going back up ontop of my truck. After looking up the Barjan 500 it looks like an antenna I wouldnt use (Looks like a nock off of a Fire stick) if it was me, but thats just me.
Also as far as the feed back, there are filters you can buy that you can put inline on your Power wire to help cut the amount of feed back.Im not sure where to buy one now, but I have used them before and they didnt get rid of all the noise, but did greatly reduce the amount of feedback.
I have a Cobra 25 "Classic" NW, and a Wilson lil' Wil 3' antenna, and i have gotten right round 12 miles with it. You for sure want your power and ground to go straight to the battery, otherwise there will be interference. The extra work of running the wires is totally worth it, its much clearer. If you wire to anything else, especially the cigarette lighter you will get interference from all the electronic components in your truck. my biggest problem was when i turned the heat/ac fan on, it would make a whirring noise through the CB, and it would get louder the higher i turned the fan up. Your best bet for an antenna, if you've got the head room, would be a 102" steel whip. If not, go Wilson or Firestik. Right Channel Radios has all the good stuff, and they're really great about fast shipping and good service. Thats where I ordered all of my stuff from. Hope that sheds a little light on the topic. make sure that before you start transmitting though, to tune your antenna to your radio, otherwise you could seriously damage or completely ruin your radio - I speak from experience. lol