Certainly, few things are perfectly heritable. 0.5 heritability (correlation), as claimed for IQ, is quite impressive.

I can list the qualities I would look for. Keeping in mind that I'm not in fact looking for sperm donors, don't have or want children, and other people would certainly want (or prioritize) other things - but that should still allow a market.

• High IQ. In addition to regular IQ tests it's probably good to look at other factors like education and other intellectual achievements - would need to research to know what to look for exactly.
• Physically attractive (would need to research how heritable this is)
• Good personality factors - high conscientiousness, etc (ditto)
• Above average height for my population, but not too tall. I remember that height is positively correlated with various good life outcomes; would need to check how tall is 'too tall'.
• Racial appearance matching mine and my partner's, and presumably also matching the local socially dominant group (Ashkenazi Jewish in my case)
• Good physical health, strength (lifetime)
• Medical history without diseases that are known to be heritable (donor and his family)
• Gene sequencing to screen for known genetic predispositions to certain diseases (donor and his family)
• Donor's family known to be long-lived
• Screening for factors known to adversely impact sperm (e.g. exposure to mutagens, history of cancer, advanced age at time of donation)
• Donor should have already had children (whether natural or from donated sperm) that were healthy, to indicate the absence of de novo deleterious mutations in the donor's sperm cell line

There are many factors I would want, but I don't know how heritable they are, and would need to research. But the above list should already lead to a much better than chance outcome that would be worth a significant price paid to the sperm bank, if I trusted the bank to ensure these qualities (to a certain degree of certainty, etc.)