Need a some help on getting parts

Hey,

I am new at all this, and I have been searching ebay.ca in search of a couple of cars to start off with.

My question is, can I have a few search tips on how to find sets of wheels and other little parts to put into the cars? I can find the models themselves, but I am having no luck with finding the acces.

I live in Canada, but I wouldn't have any problem ordering parts or cars from the US, can someone tell me a couple of good american sites that have parts and also models?

Thanks for all your help!!
J