I don't think there is such a thing as 'the traditional family' anymore, unless we define it as one of infinite variety. Times change and our lives with them, and if homosexual couples are capable of providing a loving, secure and stable home for their kids without the input of a 'parent' of their opposite gender, then that's fine. Many kids grow up without fathers in their lives, or even father figures (ie. stepfathers etc). It doesn't always damage a child.
Dr Cole may be correct in stating that children need male influence in their lives, but he fails to address the fact that many fathers have the worst possible influence in their kids.
That said, I think this legislation should include male couples. As you said, not to include them would seem to amount to sexual discrimination.