Get the s40 AWD t5 but in a wagon. I had a Focus ST which had the same engine but was front wheel drive and that engine is awesome. With just a ecu tune you can get 270bhp and around 300 with intake, exhaust and intercooler. I was running just shy of 300hp and my fuel economy was running at 7.5litre/100kms on the highway :).
Im currently driving a MKV R32 golf and am selling to buy a MKVI GTD. The GTI is awesome in stock form but after my FOCUS ST front wheel drive really shouldnt be pushed over 290hp, unless you have a lsd + suspension setup which will be pricey. So I cant see the point of buying a gti when the 127kw diesel is so much more fuel efficient/cheaper to run, + in stock form it feels just as fast.