Actually if you are the one thats bringing the parts across personally you normally only "have to" pay duty (key words, have to ). Some items there will be extra taxes and junk but parts is nothing to worry about, and as long as its bring a few items across at a time, then no duty needs to be paid. (theres a limit to how much per day you can bring, and also if you don't have a reciept with you they can't say you bought it down there).

Curious, what all will you be ordering?