Hi, In theory you could be an egg donor but it may be difficult for you to go through the medical treatment. women with PCOS tend to vary in the way they respond to fertility drugs. Even from one cycle to the next ie. one time you might not respond and then next time be overstimulated. They will need to monitor you very carefully as you can become very unwell if you overstimulate. Until you start the drugs you just won't know. The other reason I say it will be difficult is that you may do a donor cycle for someone and it be unsuccessful and that is emotionally very draining on both you and the recipient.
Recipients of eggs do like to know the donor's medical background and the clinics will ask but it is unlikely anyone is going to reject you because of PCOS or thyroid issues.
They might do gender selection for gender specific chromosone problem but I don't think they would do it for something like PCOS.
good luck