Single antennas are the way to go these days, Ive had a Wilson Trucker 2000 for about ten years it works as well today as it did then, My Cobra CB has the big finals and its been tweaked, and tuned, I use a Noise cancelling mic with Talkback. I often have guys asking me about my AMP.....Its not a fancy setup or expensive, its clean and walks the dog, its simple....my radio is an OLD Nightwatch Cobra thats got an easy million miles on it and its been in and out of several trucks....
Simple is better, all the bells and whistles, Amps-Boosters-Fancy Dual antennas pointed forward etc dont have anything on this old reliable setup...
Most guys simply install the wrong coax, MINI COAX IS JUNK....use the good stuff, Buy it from a CB Shop or a reputable dealer with the ends installed and TEST IT, I recommend you buy one of the hand held SWR testers as the built in ones can be thrown way off due to the nature of the meters design....
Ive used many good CB shops and I suggest you have any radio etc you buy tested with a SWR/WATT/MODULATION meter installed so you can see what the actual output is,
Astatic PDC2 - 100 Watt Power & SWR Meter
The PDC2 test instrument is a compact 3-function test meter designed to indicate the condition of any 52 ohm antenna and antenna coax used for CB radio operation by testing for Standing Wave Ratio (SWR), relative RF power, or field strength. Tuning of transmitters can also be accomplished when using this meter as a field strength meter. Also, comparing antennas can be accomplished with this meter. It is designed to be used for base stations or mobile operations and can be permanently installed in the antenna system without any measurable loss of power.
Features
Maximum Power Input: 100 Watts
Frequency Range: 24-30 Mhz (HF)
SWR Accuracy -/+ 5%
RF Power Accuracy -/+ 10%
There are better versions made by DOSY, but the price is considerably higher, but again you get what you pay for...