Fuel pump and volume. The thing you want here is volume...not pressure. There are plunty of formula's out ther to help you figure it out. If I had to guess I would say your stock pump is in the area of 50-60gph. Not enough for a turbo application. Turbo's love there fuel. You could do a couple of things. One would be get 2 welbo 255lph pumps tie them together drop them in the tank, and "Y" them together. The false panel on the top of the tank can be drilled out, and larger line and fitting installed. You will also need a good fuel pressure gauge. After your set-up is complete you'll want to keep an eye on pressure as boost and revs increase. If at anytime the pressure starts to drop when revs are coming up, then that means you dont have enough volume.
You 6 cylinder guys are lucky. There are a $hit ton of piggyback ecu's you can use. One that comes to mind is the Greedy Emanage Ultimate. You have an airflow, ignition and fuel maps. You can compensate for larger injectors also. You just enter the stock size injectors, enter the new size and your done. It will automatically create an initial fuel map for you, that you can tweek. Iv tuned several Mitsu's with these and they are very straight foward. AEM also offers a piggyback that will work on 6 or 8's(this is the only one I can use). A bit more pricy at $1K vs $600 or so for the Emanage. You can also use a Emanage Blue(older version). You can get these for about $300, but you cannot retard timing with that one. Only advance.
Dont forget to get a good A/F ratio gauge, and EGT gauge when your tuning it. You want to stay below 1000 celsius. I always get an EGT gauge with a warning light and set to about 950C. anything over 1000C your running to lean/hot and you'll start to melt pistons.
Hope this helps and good luck.