if you dont mind going 5 stud you can get 288mm hubs from a MK3 VR6, then fit 312mm calipers n carriers off a MK4. This will probably mean you need to upsize your wheels though, and MK2s generally dont suit anything bigger than 16inch (imo)
for the back you're pretty much stuck with the stock size, afaik the larger rear setups will only go on AWD models.