Well (broadly speaking) there's no point surely discarding, elements of an otherwise good engine.
I suppose depending on the extent of damage to your engine, and whether or not its launched a rod through the side, or caught at the noisy stage.
Four years ago I had an 82' porsche which actually went though a set of shells in a very similar way to these nissans.
I looked around for a. Suitable replacement, in the end I gave it to a 'specialist'
"We'll only use parts from people we know" blahblah....
Perhaps you can see where this is going, it was possibly my most expensive mistake
(To date)
Consequently I'm more than a little sceptical about people offering all singing all dancing donor parts, in the similar circumstances again I'd either:
Get actual part repaired if still viable,
Or,
Trade car away,
Unless I found a donor crashed car and could fire motor up in-situ.