I believe you can be a leader and be single, without a doubt. If your heart is set on the Lord, on His plan, will and purpose, and if you are focused on purity and righteousness, you wil be able to maintain righteousness in leadership through the strength of Jesus and Holy Spirit. I am single and not at all looking for marriage or a spouse or any such thing. God has called me to leadership as well. My life is trained on a path of radical purity. I am not afraid but I am also not foolish so I establish firm boundaries that will never be crossed.
My pastor, who is married, never allows a woman to ride up front in his car if he ever has to drive a woman somewhere alone or if his wife isn't present, which he would only do as a last resort. If you set yourself up to be above reproach and keep yourself out of situations that can reflect poorly on you or place you in temptation, there is no reason as single person cannot lead.
May God bless you in your journey to leadership. Remember that standing up for Christ, especially as a leader, puts a huge bullseye on you for the arrows of men and the devil alike...so keep the armor of God on.
