All the turbo stuff will work on the NA motor, interestingly enough, without any dramatic ill effects I've been told several times. Note the turbo injectors have a resistor module, if your turbo motor harness is good I think I'd use it and the turbo injectors. There are other pretty small differences, but from my looking over the wiring diagrams awhile ago I think it'd be pretty easy. Or, you could swap everything from the NA car, it's not that hard. You would need the ignition harness and module as well, they are different, but not dramatically as far as the wiring goes. From my notes on the possible swap one could re-pin either harness and plug in the respective control modules, looking at the diagram.

The trans will bolt up fine, there is a kickdown and/or line pressure cable that needs to be fitted, should be a bracket on the intake or throttle body, I don't recall if they used a vacuum modulator or not. If your turbo car is a stick it'll swap fine too. And be much preferable. I dislike autos.

Under dash vac is mostly for cruise control and a lone somewhere in there to feed the vacuum tank for the heat and air controls. There is a line to the boost gauge, but that's trivial. Seems like there is a boost limiting solenoid too, but I might be thinking about Saabs.

All in all either way you go I don't think will be too bad. If you stick the turbo stuff on the NA motor I think it'd be ok. Be conservative with timing, use good gas, watch the boost. The higher compression and weaker pistons are not a good combo for boost, let it knock much and it could crack one. But they are all very durable motors, people turbo non-turbo volvos all the time.
Are you gonna get it running and sell it or keep it?

I've put a fair bit of thought into this swap, I'm not crazy about turbos in general for daily use, and there is a bit more power to be had in the NA motor, not turbo level, but close, and with a more traditionally pleasant powerband.
But that's just my opinion.