The hub carriers (wheel bearing housing's) on the 8v and early spec 16v have integral carriers, so for the upgrade you'll need the following:
Hub carriers
Hubs
Caliper Carriers
Calipers
Ball joints
Wheel bearings (best to renew while off the car)
Discs
Splash Guards (not essential)
I believe the G60 hubs are the same as the 16v, but use larger brakes and discs (280mm). I've also read some have done the upgrade to 16v without fitting a new master cylinder, although you will get more pedal travel as the calipers are larger and require more fluid to operate. However if going to g60 brake you'll almost certainly want to upgrade the MC as the brakes are bigger still and pedal travel will be greater.
If your interested I'm doing this upgrade to my 8v, and have a spare set of hubs (powder coated), and my mechanic has a spare set of new vag 16v calipers (he ordered a set from VW and I had ordered a set from VW (miscommunication), as both were special order nether of us could return a set

)