Sounds like you are on the right track.
As for the rocker ratios, the best way to tell is by trying them. There's no real way to tell if there's a benifit from them because almost every engine acts differently with them. Why this is, I don't know. See if anyone you know has a set that you could try out before you spend some money on a set. Although, if you don't have roller rockers already, and are considering buying a set, I would go with the 1.6's. I've never heard of them hurting performance too much...