Looking for a new antenna

I'm looking for a new antenna. I have a Pete with a flat top sleeper and my antenna mount is in the middle of the sleeper right above the sleeper window. I find that going down the road I can't hear other radios behind me worth a darn. This is mostly when pulling my cow trailer. Pulling a flat it's better (for obvious reasons) and even a standard dry van it isn't as bad either. I currently have a browning antenna, not sure of model, and am looking for something that might work better. A couple have suggested just putting a fiberglass Francis on but just taking suggestions before I do that. Thanks in advance for any opinions or advice.

 

I have a 4 ft I just bought cheap today, they didn't have a 5.5 or I would've gotten it.
Budget isn't really as much of a concern is having something strong and reliable. I should pay one of you experts to put me something good together.

 

Yeah I doubt my coax is top shelf. I cringe thinking about all the interior I'd have to dismantle to swap it though. And even if I did I'd have to get a tool to crimp the ends onto the new coax...what a pain. I'm not sure of the quality of coax the factory would use, but I doubt it's that high quality.

 

I'm in west KY, about 45 miles from paducah. I'm sure I could manage routing a new coax, it's mostly a time thing. I would like to have someone reputable though check everything out and maybe set me up a little better.