new electrical parts?

where do yall get the correct factory appearing voltage regulator for the alternator, and also the starter relay for a 1968 V-8 automatic car? also need a resistor...

I have seen a couple NOS pieces on ebay, but, 70 bucks for an NOS starter relay? 40-50 for a voltage regulator...does that sound right?

or do yall just go to like, NAPA, or Oreilly, and get em there? i like stuff to look correct...