I would just like to point out Mat Latos has a 1.67 ERA at ATT Park in 43 innings (6 starts). The only parks he has a better ERA are Turner Field and Tropicana, but that is only 2 starts and 1 start, respectively. That is why I like Bailey and Latos on the road.
I personally would go Latos, Bailey, Cueto, Arroyo, Latos. The only problem there is if it goes 5 and the Reds win, Bailey becomes a 2 time pitcher in the next series. Yet I definitely want Latos pitching twice vs. the Giants. He loves him some Giants (2nd best ERA of any team he has faced on a regular basis), and especially loves ATT Park. Of course Cueto is also good vs. the Giants, but he is not the same pitcher right now.
On the other hand Arroyo is rather mediocre at ATT but has made the Giants his bitch at home. Homer just sucks all around vs. the Giants, and Cueto (as mentioned) is good either at home or on the road vs. the Giants (although better at ATT).