Mk2 Engine Transplant Problems- 1.8 Scirocco into 1.6 Golf Ryder ????

[Yeti Bwoy]

Been trawling the web and asking all around me but with no luck...

I have recently acquired a J-Plate Mk2 1.6 Carb Ryder with full VAG history, very good example but 124k on clock.

Head gasket is on the way out, so rather than shell out for a straightforward skimming etc I have decided to branch out for more power.

I have acquired a 1.8 Carb engine from a J-Plate Scirocco which was in a heavy roll. Engine was rebuilt (though not bottom end) 2 years ago by a professional mechanic friend of mine. I want to do transplant, but am worried about problems such as...

Clutch/gearbox - Will need a different one?
Engine Mounts - Compatible or not?
Exhaust Positioning
Engine Electrics

Basically I NEED HELP ON THIS before going ahead with it.

Would it be worth doing or would sourcing future parts cause more problems than it is worth?