Top loaded antennas for Cascadia

It’s time to get better CB clarity and range. Step one will be finding the best antennas for the job. My understanding is that top loaded work best on Cascadias. I’ll be running duals. The mega I work for will need to install them.

I’m thinking 7ft. Firesticks. Are they commonly available anywhere at truck stops? Any similar alternatives that work as well that I should also look for?

I’m thinking of buying two 18’ runs of Wilson cable, the stuff that is sold everywhere. That will be too long and need to be coiled. Is that okay?

How about grounding. Is there anything that I should have the techs do or install?

 

My understanding is I’ll get better coverage with duals. I don’t listen to AM/FM radio also.

 

Thanks. I’d prefer exact length but it looks like off the shelf is 18.

 

I picked up 2 - 4 foot Firestiks.

Any opinions on cable? My choices appear to be either runs of 12 ft. Roadpro, or 18ft. Wilson. I’d prefer to go with Wilson, but I’m wondering if the shorter, but generic Chinese cables would be better due to overall length. Custom cables are not an option.