Beofre i went the greys route my stage 3 consited of:

T34.48
-31 actuator
Group a coil
Greens
500 intercooler
3 Bar Map sensor
Group A Headgasket
1.7 Bar of boost
Fuelling controlled by a genuine ahmed bayjoo chip
Ap Organic Clutch
Full Mongoose Exhaust
Group 'a' K+N cone filter (not essential)

Water injection is another good thing to have but not essential.

Radiator needs to be half decent as well