We all recently discussed a topic along this topic: should Christians marry others of different colors/cultures? Someone wisely pointed out that there is only 1 race: the human race! Absolutely true.
The thing that helps decide if a Christian should marry someone is: are they or aren't they born of the Spirit? If both are solid believers with a Christ-centered relationship, are single and desire to marry there is no reason they shouldnt.
Culture differences may make the marriage more challenging (more interesting, even!), but should not prevent two believers from marrying. They will need to communicate, communicate, communicate;pray together often, be p-a-t-i-e-n-t with one another, and be long suffering. But hey! When doesn't marriage need that, anyway?!