I've had a look at the wiring diagram and the parts list, and fitting folding/memory/heated mirrors might not be too bad. All the wiring seems to be inside the door. And the door modules are all the same whether the mirrors fold or not. The only difference in the modules is if you have one-touch up windows or not.
So you would seem to need...
The folding mirrors with the black and white connectors. For both doors.
The wiring in the doors from the same car.
The switch in the driver's door.
The link between the two sides of the car is by the computer I-Bus, so no wiring needed in the car. So a Tech2 enabling needed.
That's what it looks like.
I think that it's quite do-able!
I think =that you may need to re-wire the door as the mirror to module wiring looks to be in one loom, but I'm not 100% certain. It's 8 years since I had the door completely disassembled.