forget the hydro, I'll repeat it like a broken record.. it's great until it breaks or fails, but then it's time to go 2J mechanical.
you'll want a MKIV TT fan clutch and fanblade, or if you want more clearance, use the SC300 fanblade w/ spacers (for stock rad fitment). By using the SC300 blade, you can trim the back of the blades to clear the water neck and still run an upgraded radiator. Many of my friends such as BigzAvs (on here) have run this setup, and I have as well.