any 2 liter lump with a turbo, every psi of boost will yield roughly 10BHP and 10lbs foot on the right engine.
thats if you want all out power and silly straight line power (once the front wheels stop spinning)
For a Day to day car the 8v has it out the box, good flexibility for town and b road blasting and good at cruising.
If I was going to build a track day Golf , Id want a high rev 2.0L NA with 8500K rpm to play and 180 - 200HP and a LSD in the gearbox.
My 8v golf is a more rewarding drive than my Mr2 turbo , because I have to actually drive the Golf to get the most from it, In the Mr2 its rare to use full throttle as you end up doing silly speeds and running out of road with out trying.