you will get the pins and the male-female plastic connector make sure red to red black to black and push till they snap in
i have never used the tamiya site but i buy all of my stuff from towerhobbies.com. They will have anything you want
IF it is an origional Lunchbox, and in good condition, it may be worth some money. As a running rc car, they are fun to play with. Almost anything by Tamiya is pretty good.