Where/how can I have a Christian marriage done but 'register' it legally in 6 months?

My fiance and I would like to be married, to stop outside of marriage, but don't want give up the last 6 months of her significant alimony. We will continue maintain separate households and have no joint accounts(not cohabitating) to adhere to the 'letter of the law' in the alimony agreement. So, if we want a minister to marry us, in God's eyes, but be married in the state's eyes, in 6 months. Opinions and ideas please!