He has contacted her several times saying that he wants to propose marriage, but she does not know anything about him

I am a Muslimah, age XXX, from XXX. I accepted Islam 8 years ago when I was 16, Alhamdu lillah. For all of those years, I wanted so much to be a Muslim wife and mother, but since I live in a very small Muslim community (XXX), this did not happen.
A month ago I sent out my resume to find work in an Islamic school in a large Islamic community. The imam of an Islamic center in Florida left several messages on my answering machine. Days later, a brother called from the same masjid and said that he had lived in America for 10 years (he is originally from Saudi Arabia) and was looking for a wife. He is over thirty. He said that he wanted to marry me after he read my resume. (The imam gave him my resume since he knew he was looking for a wife.I was a college student of Islamic Studies.
I live with my mother who is a Muslim, but I have no male Muslim relatives. I do not know any Muslims in Florida either. This brother has continued to call me and talk to me while my mother is nearby and he also spoke with my mother and told her that he wanted her permission to marry me.
I want very much to get married In Sha' Allah, but I am very worried. I feel very vulnerable because I do not have a Muslim male relative who can check this brother out. Sadly I have heard of brothers who come to America and date women for years, or are involved in other bad activities. I am worried about this.
He has talked a lot about his love for Islam and da'wah. He says he is so happy that I have a Muslim mother and he wants me to support me if we get married and possibly move to Saudi Arabia. But I was worried also because he said that he has had a beard most of the time, but has on occasion shaved it off. This concerns me because I know keeping the beard is important and is Sunnah.
The most important quality for me in a husband is both his belief and practice of Islam. Books I have read on Islamic marriage say that you will never find a perfect spouse, but to look for their religiousness. How do I know if this brother is good or not? How do I know if he is really committed to islam? What should I look for? Please help, In Sha' Allah.
  I just submitted a question and wanted to add something extra: the brother who wants to marry me has been calling me every day, sometimes twice a day. Also, he has never seen me either in person or in photograph, but still seems certain he wants to marry me.