Hi Adam, OZ do the Ultras for 15" upwards. 15" price is around £600 I think for a set of four with tyres. Go to topgear.co.uk - that is where I bought mine from and they are really helpful.
I have had to go with a mid tint visor (helmet is white) as the black one would be impossible to see out of indoors or in low light. I just need to get a head up display in there now like they have in fighter planes - how cool would that be!
With regards to discs I would get the best you can afford always, AP Racing are market leaders for a reason with a good pedigree in racing. Mintex, Pagid, the list goes on and I am not the best educated for an opinion - I tend to ask the bloke that does my track day tuition as he has been racing, tutoring and speccing his own for many years.... he is my car bible! If he says no then no it is!!
Not sure about vmaxx, I am still researching into suspension options for mine... but the price sounds good!
I like the vinyl and the debadge on the front - looks really agressive. I bought the honey comb grill to do mine but after 3 hours of trying to get the bumper off and blood everywhere I realised SEAT had ordered me the wrong part!! I was so close to kicking a puppy you would not believe!! I'll post the pictures one day - car looks weird with no face!
Do you have a plan to go on the track with yours? Diesels shame a lot of cars on the track!