Are you looking for a mate or are you looking for a friend?
If you are dating and are looking for a mate, it will be tough to become friends depending on your maturity level.
If you are just looking for friendship in general, I think it will be relatively easy for opposite sexes to be friends no matter what the sexual orientation. Commonalities, general likes and dislikes, whatever, the bonds of friendship are shared when one keeps a perspective on the purpose of this relationship...
Whereas, seeking a mate is different. Eventually, those involved could be friends. However, there are many ways to express one's mating habits. If one is attracted physically and sparks fly whenever they are together, then it will be extremely difficult to build any kind of friendship relationship.
That thing about agape and eros...
At any rate, personally, I do not have very many male friends. Especially now that I am married. And my husband has very few female friends that I know all about. Most of the ones I know about are married with children. Besides if he wanted to get with one of them for whatever reason, he knows he'd be giving up on the best thing that happened to him