I'm afraid that you and your fiance have been doing too much reading about marriage from a Fundamentalist Protestant perspective rather than a Catholic perspective.
Catholics believe that husband and wife mutually submit to one another out of reverence for Christ. For a husband to assert that he has the right to "spank" his wife because she is too "defensive" or "stubborn" and for her to be willing to "succumb" to him because he is "head of the house" is an extremely non-Catholic understanding of marriage. And, from a purely practical point of view, it is also extremely dangerous. A husband who feels he has the right to curb his wife's "stubborness" may progress to making her completely dependent upon him -- especially since such "domestic discipline" is not reciprocal (i.e., the husband is never the one who must be "spanked" for his bad tendencies).
To be perfectly frank with you, if your fiance has been telling you that he thinks it a good idea for him to "spank" you to keep you in line during your marriage, then that is a huge red flag that this is someone you should NOT be marrying. I can only recommend that you seriously reconsider your plans to marry this man. However difficult it may be right now to end your relationship with him, it will be nothing in comparison to having to flee a physical abuser later, perhaps with terrorized children in tow.
Are "traditional" marriages okay in the Church?