Heres what I decided on getting!
 

Ok talked and talked about this set up.

I finally decided to go with twins using my stocker with a s400. I know some of you guys are running this set up. Do you like it? How much boost are you making? I am also getting ARP head studs, valve springs, and a set of F1 injectors. Do you think I would have to have a lift pump for this set up?

i don't have twins but it sounds like your gonna have a pretty wicked truck there!! i also don't see any kind of an aftermarket lift pump in your sig so i would think that with the smarty and f1 injectors you would definitely need a lift pump. also depending on the size of your injectors, you may to upgrade your cp3

Definatly need a lift pump, and you might want to think about some CP3 upgrades.

I have an AD150 as a lift pump, I love it, install was great, works great, ect.

If you have the coin throw, get a stage 3 CP3, duals if you don't ever want to worry about fuel again, or if you want to stay cheap, get an Arson II CP3 mod kit, mine supports my mods easy, and was only about 375 shipped.

Sweet sounds good and exactly what I was expecting to hear. I should be in the 550 hp range after im done with the twins and injectors etc. I have no further expectations of mods, so would I be ok with just a lift pump?

what size are the sticks?? I am running that same charger set up and when i ran 110hp ddp's i was draining the rail bad. so unless your going with small sticks i would also upgrade the cp3.
as far as boost, when i had stock sticks i could barley hit 50 with stacked boxes, but now with 3.5's i am making around 65psi

they are going to be the 90 horse stix from F1.

Get the lift pump for sure - i would guess the CP3 will at least need mild upgrades as well.

A lift pump would be a must with that kind of fueling. You are going to be very close to needing to mod the injection pump. The Flo Max pump at 165gph will keep up with the demand of the CP3, but it doesnt matter how much fuel pressure you put to the CP3 pump it can only put so much fuel into the rail.