Welcome to Nico!
The GT2871 is a great turbo for the KA. You're going to want a FMU, fuel management unit. The FMU is a rising rate fuel pressure regulator. Which means for every 1 psi of boost it will increase the fuel pressure a predetermined amount. I'd say you're going to want a 6:1 ratio or 8:1 ratio.
Meaning they will increase the fuel pressure 6 psi for every 1 psi of boost. I would also highly recommend a new in tank fuel pump, summit sells a 255lph pump,
http://www.summitracing.com/parts/vpn-gss307/overview/ I don't think there is a better deal anywhere.
The FMU can be found online from several vendors. I only have experience with Vortec, but I hear that Blox and OBX are also reliable, but that is just from other members here.
You don't want to add boost without some sort of additional fuel.