Suspension wise I would either leave it alone as it is very good on the handeling anyway or go for a set of Konis on it. Brakewise MK3 calipers with ST170 discs gives an instant upgrade from 276 to 300mm. Or the Focus ST225 calipers and discs fit to make it 225mm but a lot more money.

I run a pair with the 300mm conversion and they are a huge improvement over standard.