I have Sugar Pearls, Lasrgerdi Mashhad, Cot’n Candy and White Knockout (all are white cots). While Sugar Pearls is good, the other three are significantly better. I would recommend White Knockout, which is self pollinating, heavy producer of very large, very tasty and sweet apricots. It is also a few weeks earlier than Harcot (or Blenheim), so you would get good spread of your harvest. It is available from several CA nurseries, including Bay Laurel:
Notes:
1- Blenheim is self-pollinating and does not need cross pollination.
2-Harcot is mediocre tasting cot, I would top-work that tree with another variety. There are so many better tasting cots out there. See the links below for some examples: