Confused

I am in a situation that I really want to resolve. I am in a loving relationship and unsure if I should take the next step of marriage or not. My boyfriend is 52 and I am 29. We have been dating for four years and everything is truly great. He is now thinking we should get married. I am worried about the age difference and having kids. He has never been married and has a ten year old daughter who lives with us 50% of the time. Now it is okay but in 10, 20 years I don't know if it will be okay. My family and friends all live in a different city across the country. I am confused about staying here and marrying him or moving back to where my family and friends are. I'm worried about marrying him and having no support system when it comes time to have kids. Also, I feel like because of his age I'd need to have children right away but I am in no way ready to have children right now. I am scared about the future but the present is great. Does anyone have any advice or has anyone married someone with such an age difference? When we first started dating I never imagined we would be together and more in love four years later. Is a 23 year age difference enough of a reason to end a relationship?