Gotta do some more research. There are a lot of conflicting reports on running 1.6's without enlarging the pushrod holes. The narrow-body 1.5 comp roller rockers will supposedly fit with no modifications to the head or valve covers. The stock rockers are self-aligning and you can get the comp units in SA as well.
I'm thinking that the 1.5 rockers now would support a larger cam in the future... I really don't want to deal with pulling heads this season. That could quickly spiral out of control!