I am a Christian who suffers from homosexual thoughts sometimes. Though I have never physically acted on the thoughts in any form it is still a sin. I ask God for forgiveness and ask him for help in keeping my mind focused on him and not on sin in my life.
I believe that homosexuals adopting is wrong. Yes heterosexual couples adopt and still sin but homosexuals live in a lifestyle that is constantly in a sin that they will not turn away from. If one or both were Christians and still living in a homosexual lifestyle then God will convict them everyday and remove any spiritual peace from their live. Trust me, I know. (Again, never physically acted, just thought life=still a sin though.) If they continue to mock God by not coming to repentance then they would be very bad parents.
Now if they were not Christians but still living that lifestyle then it would not be good for them to adopt children. I think that non-christians adopting children are bad to begin with because they would not teach their children the Truth-Jesus.
However, I am not as opposed to that as I am about homosexuals adopting children. Either way, God can reach a child no matter what circumstances they are living in.