You could also grind the injector notches to the 1.6 head yourself.
2.0 injection head will flow much better tho. Dunno if you can use the extra flow on the 1.6 bottom end without blowing it up.

-EDIT- Rethinking this now, weren't there supposed to be a problem with the 2.0 heads on 1.6 bottom ends with the valves hitting the block because of the smaller bore size?