Cheers mate. Got the springs from Awesome GTI. Haven't had to touch the arch screw myself as they clear fine. There's plenty of room.
Remember to get a full alignment done once it's lowered.
Just bear in mind, some 225s are a touch wider than other 225s. Not massively, but if they have a squarer shoulder you could get the odd bit of contact. Like I said, the Supersports are a good option. As well as being a damned good tyre!