brakes, coilovers and tyres would be a good start.
If you're on a budget for brakes,
just get good pads(i've got high temp pads for the euro, both front and rear for sale btw), steel braided brakelines and high temp brake fluid.
or if you've got the cash, aftermarket calipers!
4 pot- spoon, willwood
6 pot- AP racing, endless
Coilovers, got a wide range available. Tein, buddyclub, endless zeal, aragosta etc.
tyres, get a good set of street tyres(AD07, RT615, RE01 etc.) or if you've got the cash, run semi slicks(R888,RE55s,A048,D02j,D01 etc) or get a set of track rims and chuck semi slicks on them.
as for the other mods that you've mentioned.
if you havent got a budget
Header-Maximworks (other options, comptech, Toda, DC sports, six sigma)
Intake-GruppeM (comptech, Injen, Mugen)
exhaust-Amuse! or maybe the J's racing. Both are full titanium catback systems.(5zigen, buddyclub, comptech,Mugen,Spoon N1 etc.)
and while you're at it, get a heavy duty clutch, lighter flywheel and possibly a LSD. and you're good to go!
