I don't think options are going to play much of a role in deciding the last rotation spot. Barring injury, there are 4 spots accounted for: Ryu, Roark, Anderson, and Shoemaker. They contenders for the last spot right now are probably:
Thornton (has options)
Yamaguchi (options)
Borucki (options)
Kay (options)
SRF (oprions)
Zeuch (options)
Merryweather (options)
The only relevant arm with no options is Font. I'm expecting him to be in the bullpen, because his stuff has played up in shorter outings. I don't think the team will go to him as an opener right out of camp given the depth of arms that could reasonably give them 5 good innings every 5 days.