The SWR Analyzer has quite a few different functions. Obviously it can be used to test the swr of the cb radio antenna itself. You can read the exact frequency of your antenna as well as the complex impedance. If you suspect your coax cable of having a short or open you will be able to measure the distance to the problem. It basically is a complete ham radio test station with frequency counter, RF signal generator, SWR/Resistance/Reactance/Coax Analyzer, Capacitance/Inductance Meter and with other features as well.
I have used my MFJ 259b antenna a few times when I was designing a dipole antenna for my ham radio shack. I am presently using it in the designing and building of a 6 meter quad antenna and a moxon antenna for the 17 meter band. The nice thing is that these types of antennas as well as others can be designed for the 27 MHz CB Radio band. There is nothing like building your own antenna and having someone tell you it sounds really good. These are the types of things that may lead you in a certain career path.
As far as brands go I like the MFJ brands even though some individuals shrug their shoulders at them. The newest model like mine is the MFJ 259C Antenna Analyzer . Another brand that I like is the comet brand. They make a nice antenna analyzer model CAA-500 . Here is a link to their webpage with information on it http://www.cometantenna.com/products.php?CatID=1&famID=10&childID=20 . RigExpert also makes a very nice antenna analyzer as well. My advise is to buy one of the antenna analyzers through the internet at one of the dealers, amazon or ebay. No matter which way you go make sure to check out any reviews on the seller. If you are looking for reviews on the various antenna analyzers check out Eham.net. There is an abundance of valuable information from fellow Hams that have owned, used or own one of these.
Well that's all for now so Thank You for reading.