Had a stage 3 4x4 which I bought for £4700 and thought it was great but should have spent more and got a better/newer one as the bugger cost me nearly £2000 in the first 6 months of owning it and was fed up in less than a year and sold it.

Scoobies are great fun in all formats (I've driven WRX, STi, Terzo and am considering one as the next car) and you can get an STi for very little money now or a good WRX import 240-260bhp as standard within your budget, or possibly a cheap RA. You can really let them have it and they are really forgiving, they just kill tyres though. Having said that, have you ever seen a broken down Scooby on the road??!? I haven't

GTi-Rs are not crap round corners, but they are a bit small and ugly.

Not driven an Evo so no idea what they are like but you wouldn't get much of one for 5-6k and it would be an Evo 2/3 which are old looking and nowhere near as nice as the 4.

I've looked at Skylines and been in some bloody quick ones, but too many horror stories and limited number of people who can repair/maintain them properly.

Supra TT is another choice if you like GT cars but TTs start off at the fat end of your budget. Mega quick though and strong as an Ox. Stock block is capable of 500bhp plus on standard internals (another one I'm considering at the moment).