Don't shop for parts. Shop for a good machine shop.
He will have his ideas about what will work and what won't. If you take him parts that he considers junk, he won't back the work.
He may even have good prices.
As an example, when I rebuilt my 292, I looked around for LPG pistons. I found prices of $50 - $80 each. The shop supplied them at $40 each.
Even if the shop buys at cost and makes a couple of bucks from the parts they sell you, both of you will be happy.
