Big Brake Conversion

Hi,
I have a 1983 Mk1 Golf GX 1.5
I am getting 15" ATS Cup wheels on 165/50/15 tyres
JOM Coilovers and lowering it as much as possible
I do not want to replace anything on my current front brakes e.g. hub, axle and I don't want to have to fabricate anything
What is the biggest disc I will be able to get under ATS cups and what will be the best calipers I can fit.  I would like to fit some porsche calipers I think they are the 996 or boxter ones.  But would other calipers be better like wilwood, g60 or brembo ones. And also where can I get the mounts to fit porsche calipers on?  Then would I also want to replace my master cylinder or anything else which would make them better and could you also tell me how much it would roughly cost?
I think I saw some porsche boxter calipers going for ?180 and a mount cant be too much but I'm not sure if I would need anything else?
My budget would be about ?300.00 but I'm open to all suggestions!

I also have standard rear drum brakes! Is there anything I can do to them which would be worth doing?


Cheers
Jack

P.S. sorry for all the writing but I'm 17 and this is my first car and want to get a nice Euro DUB going and not put it to shame!
Also doesn't matter how technical it is because I have already rebuilt my engine and if I do get stuck some of my friends are mechanics!

jackholmes2 said

 1.5

Yeah you'll be okay with 239 solid discs, as it has at the moment. If you want to upgrade then vented discs and GTI pads (I think the calipers are the same? If not then GTI calipers too) will do you right.

Then it gets a little more costly, because you have to replace both discs and ditch the existing calipers. I believe ATS wheels don't let you fit 280mm discs (some 15" do though - look for ones for fitment to Corrago G60) so your max is 256mm, although you might come across TSR 270mm discs (which are machined down Rover items, I believe).

So you'd need 256mm discs.

Calipers - 2 options: 1. GTI 16V or equivalent on some other VWs too, combined with Audi 80 caliper carriers - rare and expensive! 2. Vauxhall 256mm calipers from Calibra/Cavalier 16V, + 10/12 shoulder bolts and Vauxhall brake hoses.