Get Sony A7R II at B&H Photo.
Though pixel shift is not a panacea (and it can fail badly in the field for subjects with movement) and is tripod-only (at present at least), it is an awesome feature that is oddly lacking in the A7R II.
Conspicuously missing from the Sony A7R II feature set is Olympus-style pixel shift, which in my testing can deliver roughly a 32-megapixel image from a 16-megapixel sensor. On the 42-megapixel Sony A7R II sensor, a similar technology would deliver ~63 megapixels, or maybe more like ~80 megapixels using a Zeiss Otus.
It’s a pity that Sony is not offering pixel shift, since it has Olympus-style sensor stabilization. Perhaps it will appear in a firmware update, but that seems dubious, since it is a terrific feature to brag about at a product release (and would be a first for a full frame camera).
If Sony does not implement pixel shift, then the most likely candidate is the coming Pentax full-frame camera, which utilizes the Sony 42-megapixel sensor (pixel shift already exists in the Pentax K3-II). And then one wonders about Nikon, which at the least ought to offer a Nikon D820 with the new 42MP Sony sensor, though we can hope for more.