All depends on the various measurements. Keep the offset at 37-ish mm, keep the tyres no wider than 195mm and match the rolling radius and you're guaranteed no issues. 195/40 R17 is only 0.2% greater in diameter than the mk2 stock. I warn you though, you are looking at in excess of £100 per corner for half-decent tyres.
Don't forget to make sure the bore size is correct too. Bare in mind that 17" will be purely for aesthtic reasons, handling and ride will be comprimised.