Hello, did this a couple of years ago and plan to basically do the same again next year.

You will need the drive shafts from a 2.0 petrol or a 1.8 diesel, can buy new for a reasonable price.
The speedo will read way off and replacing the clocks will have no effect, I bought a unit to correct the signal but never tried it. Could just use a gps speedo etc
If you allow the engine to drop at the gearbox end then changing the gearbox is easier but it is tight, not much space under the wheel arch

Changing the gear cables is not much fun, remove one front seat then unbolt the handbrake and remove the centre console which will allow you to get at the gear lever and cables

You may have trouble removing the lower ball joint pinch bolts so best to get 2 new ones