I don't see why not. If you live America you marry who you choose. If this person is honest, caring and has good moral character why are you concern.

I am American raised Protestant and believe, as many around the world do, that you can marry anyone you want.
You are the only one who can find out what your family, his family, community, and muslim leaders, both mehdavi and sunni, will say, and how much you want to endure if they are against it. It might be difficult to even ask, I know. Hopefully you will get some replies here from Muslims.
It would be nice if it didn't matter, wouldn't it?

I think you are asking this question from a religious point of you. I think you should ask some Alim for a precise answer.

What do your parents say? What do his parents say?

U can't marry with a sunni muslim because he don't hve imaan lyk us...

I think you have to ask yourself what is your position in front of Allaah -ta`aalaa. Do you want to meet Him upon the Sunnah of His beloved Nabii -sAaws- or upon innovations that someone has invented to distort and change the pure Religion of Islam? Surely that is more important than marriage.
If, (and when, I hope) you do decide to follow seraat al-mustaqiim of Rasuulullaah -sAaws- then you can come back to the question of is he a real follower of Nabii -sAaws- or is he just saying `sunni` by name. And ask Allaah for guiding you and him both to know the Haqq and follow it, and to realize the baatil and to leave it, and ask Him for His guidance about the marriage secondly. He knows everything. He has the power over everything. He answers every prayer as long as you don`t call upon anyone or anything besides Him, and He is the best of everything. Make Allaah number One in your life, and He will give you everything best for you.