It would be Rubio over Ryan for the nomination. Ryan is going to be a hard sell. He already has an assailable record to attack and is extreme to independents, yet he can't claim to be 'more conservative' in the primary than Rubio. Rubio is all upside, -very conservative, less of a record to attacked on his very conservative stances, more charisma, more young energy, minority bona-fides, Floridian, etc. Ryan is just comes off as kind of dickish, weird looking, and extreme based on his submitted budget. Typical out of touch rich white man Republican. Come to think of it, Republicans have been remarkably great at shooting themselves in the foot with their primary choices. Maybe Ryan will get it after all.
I'm not sure how much sense that would make. An extremely conservative candidate with another extremely conservative candidate...usually the nominee will pair up with a VP that will help them expand their base slightly and peel votes off from demographics their campaign messaging wasn't primarily targeting. Two hyper-conervatives would leave independents and moderates behind in the general election. Strategy wise it would be quite a departure...