We just went bike shopping for my son today. We went to Toys R Us but also to a regular bike shop (Performance Bikes - not sure if they have it in TX). The guy who worked there said that, in the small bikes for really little kids, it makes no difference what kind you get. He said they are basically all the same - similar shape and style, no difference in how the chains and pedals are set up, etc. He said the only thing that mattered is to pick the right size.
After looking at a few brands, we are actually getting the exact bike you mentioned - Huffy Cars - in a 16." I'd really recommend taking your son to the store and letting him try the bikes on for size. If he can pedal comfortably and reach the handlebars without stretching, the bike is a good fit. Have him try a 12" and a 14" so you can see which is best - better to have one he can grow into than something he'll be too big for in a couple of months.
Good luck!