Good Luck on your paper and here is some research that might help you. There is a synopsis at the beginning and the website for the paper.
More than 25 years of research have documented that there is no relationship between parents' sexual orientation and any measure of a child's emotional, psychosocial, and behavioral adjustment. These data have demonstrated no risk to children as a result of growing up in a family with 1 or more gay parents. Conscientious and nurturing adults, whether they are men or women, heterosexual or homosexual, can be excellent parents. The rights, benefits, and protections of civil marriage can further strengthen these families
A review of the psychological research into the well-being of children raised by same-sex and opposite-sex parents continues to indicate that there are no reliable differences in their mental health or social adjustment and that lesbian mothers and gay fathers are not less fit as parents than are their heterosexual counterparts. The opposition to marriage of same-sex couples, on the grounds that it fails to consider the needs or rights of children, does not consider the most relevant body of psychological research into this topic or draws inaccurate conclusions from it. Further, opposition to marriage of same-sex couples often incorrectly pre-supposes that, by preventing marriage of same-sex couples, no children will be born or raised within families where parents are of the same sex. Such as argument ignores the reality that children are, and will continue to be, born to and raised by parents who are married, those who are unmarried, those who are cohabitating, and those who are single – most of whom will be heterosexual, some of whom will be gay, and some of whom will be lesbian. Further, the literature (including the literature on which opponents to marriage of same-sex couples appear to rely) indicates that parents’ financial, psychological and physical well-being is enhanced by marriage and that children benefit from being raised by two parents within a legally-recognized union. As the CPA stated in 2003, the stressors encountered by gay and lesbian parents and their children are more likely the result of the way in which society treats them than because of any deficiencies in fitness to parent. The CPA recognizes and appreciates that persons and institutions are entitled to their opinions and positions on this issue. However, CPA is concerned that some are mis-interpreting the findings of psychological research to support their positions, when their positions are more accurately based on other systems of belief or values.
Relatively few studies have directly examined gay fathers, but those that exist find that gay men are similarly fit and able parents, as compared to heterosexual men. Available empirical data do not provide a basis for assuming gay men are unsuited for parenthood. If gay parents were inherently unfit, even small studies with convenience samples would readily detect it. This has not been the case. Being raised by a single father does not appear to inherently disadvantage children’s psychological wellbeing more than being raised by a single mother. Homosexuality does not constitute a pathology or deficit, and there is no theoretical reason to expect gay fathers to cause harm to their children. Thus, although more research is needed, available data place the burden of empirical proof on those who argue that having a gay father is harmful.