Obviously there are decent Christian guys out there.
Far as dating with the intent to convert (known as 'missionary dating) consider a few things.
-What if he influences you more than you him? (and don't say that can't happen, it can and does and if you think you are above that then your pride will definitely cause you to fall)
-What if he never gets saved, how long will you date him then?
-When you reach the point where you've gone long enough and he still doesn't get saved what kind of witness will it be that you dump him because you couldn't change him into what you wanted?
-What if he fakes being saved just to pacify you?
-Is it really and honest and sincere approach to date someone with the intent on changing them?
-How would you feel if you learned someone you dated was only doing so to change you, would you still want to be with them? Would this encourage you to look into their beliefs? Or would you be hurt and possibly view that set of beliefs, and that person, in a negative manner?
-What if you are not able/willing to emotionally end the relationship because you became close and are now stuck with a non-Christian?
Now, lets say you marry this guy. How about these questions...
-How will you enjoy spending the rest of your life knowing the person you chose to enter into a covenant between you, that person and God is bound for hell?
-What if they die sooner than you think? Are you prepared to live the rest of your life with the knowledge you gave your heart to someone you would know to be in hell?
-What if you have children? How will you explain to them the importance of your faith while also telling them that you picked someone who did not have the same emphasis on faith as you?
-How do you explain that you selected for them a parent that will go to hell?
-What if your spouses lack of belief affects your children's belief?
-If the bible says the man should be the spiritual leader how could you pick someone who is unable to fulfill that role, and then believe that is what God wants for you?
So your options are to be deceptive and manipulative in an attempt to change a person to what you want. And if they don't conform you ditch them, essentially treating them as a thing rather than a person.
Or be with someone who is unable to perform the duties of spiritual leader over his house and children while living with the knowledge that this person will not be in heaven?
Or go live your life and pray that if God wills you to be married that you will trust Him to find the right man for you, not one you lowered your standards to have.