LIKE IT! Diffs may be different. Put one end front, then back in the air, mark the drive line with chock spin the wheel one rotation to figure out what gearing you have in each of the axles. One of the common things to do is to use the gearing from a stick behind an auto to give you some mechanical advantage. If I was there I would be saying for sure the 1.6 with auto is the way to go ( I drive a 1.6 with manual).
Calmini lift is a good thing, usually very complete. The only thing to check is the A-arm for the rear diff. If it is not there then talk to Jeff.
Gearing match up is fine as long as both front and rear are the same.
What kind of lockers are we talking? ARB? mini spool? limited slip? stock or aftermarket?