How deep are the outside walls? (i.e. jamb depths)

We have 2x6 construction

Both should be options then. Just depends on what you like, I supposed.

Inside mount cuts light out better IMO. There are still tiny gaps on the side (my husband abhors any light in the bedroom). We have installed top down bottom up blackout honeycomb cellulars. We like Levelor the best - no problems.

The advantage of top down shades is you can look out yet have enough privacy.