I have no idea about either the ESC or motor, so this is probably redundant advice...
however, if as you say the ESC burnt out "as soon as I connected the battery" then this sounds more like you connected the + and - leads the wrong way round. This fries ESC's instantly, either that or there was a short in the esc itself (i.e. warranty will cover it)
double check your + and - leads to make sure you dont blow whatever new ESC you choose.
Sorry to hear your son's upset - you'll get it fixed soon Im sure.
What about travelling to one of the good model shops that are open tomorrow - MB Models and JE Spares are two just off the top of my head that are definately open tomorrow,
Take your car with you and they can test your new ESC right in the shop and advise on just the right one.
Good luck m8.
