Can I set a CPA per product and use that in my Google Search campaign?
Yes: If you want to set a bidding strategy that focuses on conversions (Target CPA), you can set a Max-CPA from your feed or by setting it as a % of the price. You can subsequently set you Target-CPA as a % of the max.CPA. You can set it as 100% (then it is the same), but you probably want to take a lower % because Google often targets within a certain margin. Also: you want to make a profit, so keep some of your margin.