20'' wheel size ,and roughly 25 pounds in weight ^_^
The BMX bikes that you buy at Target and or Walmart are not the same BMX bikes that are used in BMX Racing and BMX Freestyle. Real BMX bikes are lighter, they have diiferent size sprockets among many other things. Feel free to google the National Bicycle League or the American Bicycle League to get more information.
I would buy the next size up from his pants size. If he wears a 12 I would get a 14
I wouldn't recommend a mongoose, but I would go with ace.
One can buy a custom BMX bike in Las Vegas from a few stores. One can get a BMX custom made from 'Just BMX', 'Bolder BMX', 'Bike World' and 'Vegas Bike Store'.
The size of the tire is usually embossed on the tire sidewall, then just buy a tube in that range. Make sure you get the right kind of valve.
at the entertainer
Sunday
dk
in toysrus
build it custom yourself
at the warehouse or framers
it matters what you are going to use it for