What's in a (donor) number?

The more we look for a new donor, the more I question what we should be looking for in them.  We're well aware that for the most part this was done as a means to earn money.  So when the application asks why they donated, we appreciate honesty with a dash of "I wanted to help people."  The variety in donors has been narrowed even though the numbers have been expanded. Other than potency, I'm not sure what I want in a donor or what my wife wants. We have mentioned taller (I'm a shortie), hopefully of mixed or other than Caucasian heritage, and someone that seems to vibe with our likes/dislikes.  It just seems odd shopping for a product to help make our child.  Anybody willing to share what helps them narrow down a donor?
A big question that has come to mind lately is known vs unknown vs willing to be known.  There were only unknown donors at our last bank and at the time that seemed to flow really well with what we wanted. This was our dream child and if they should actualize they wouldn't need to meet the donor.  The more we search, the more cruel that seems.  My father was a product of closed adoption and faced unique difficulties. I think that an unknown donor closely resembles closed adoption. However, having a willing to be known donor doesn't guarantee the donor will still want to meet or the child will either.  There are rules and regulations in place to keep this our child and only allow the donor to be sought out at a specific time. Then there is a known donor...... insert cricket chirps here. Too many horror stories both real and dreamt up. Plus by the time you pay for all the testing it can be just as expensive as a bank.  It's good we have time to ponder but I think I might take to the community boards with these thoughts. It's nice to have other people to bounce ideas off of.