****JUST LEARNING NEED HELP*******
Ven
With the exception of the Futaba Candy (I am not familiar with rc boats), all of the other vehicles are pretty dated. I have a KO Mars (EX-1) and it is a very capable radio (even when compared to newer high end radios). I guess if you are going to bash around the house or compete at the club level, the B3 and 12L3 will work. Getting parts may become an issue as the B3 and 12L3 have been discontinued for quite some time. The dirt thrasher sounds like a Tamiya 4wd buggy. It may or may not be in production. How old are the batteries and have they been cycled (properly maintained)? The overall condition of the batteries will be an issue if you are planning to compete at any level. If you are buying the cars (and boat) to play around with just make sure you know what you are buying (is everything in working order). Anyway, welcome to the hobby and have fun.
llamont