I asked three guys already and they have agreed to be donors. Although two of the 3 are married, but my problem with the 3rd is he's single and insisting on being in the child's life.

Like you mentioned, the donors may sign a weaver on parenting responsibility now but when the child grows they will be entitled to be in the child's life.

That's why I'm considering choosing a donor who has no close connection with me. I really do want to have my next baby for myself. My experience with sharing my daughter with her father is something I wouldn't want with my unborn son.