MaryWong, any suggestion here shouldnt be put into ur relationship.
In any case ur going to marry him, its going to be a Buddhist-Christian.
A mix, in a simplified word. There is nothing to choose about.

I understands how a strong Christian believer would be and a Buddhist as well.
Something to share, I have a relative whom his dad is a Christian and mum a Buddhist.
They go to Church together on Sunday and to the Buddhist temple, i.e Wesak day. Its needless to ask ones to convert.