NX for sure
Not to forget that direct port requires you to pull the intake manifold unless your crazy and want al those metal shavings in your motor.
I personally keep nos on the safe side and run a 50 shot wet right before the TB. I dialed it in on the dyno last weekend and it kept very smooth and consistent A/F readings. I also killed my plugs by the third run and possibly blew up my wastegate. But thats another story.
Keep in mind that when running NOS you must Gap your plugs down. I recommend .28, any higher and you risk the NOS blowing the spark out and then the likely hood of Nitrous Backfire is high! (happened to me even at that gap due the plugs getting taxed) I swapped my plugs out at the dyno and they lasted 3 runs on NOS. Total! So keep that in mind too, NOS kill splugs.
I am currently running the NX kit and really like it. The switches that the kit comes with are big gawdy hick switches but you can get something a bit more tasteful at your local electronics store.
I chose the NX kit because the selenoids on the smaller shot kits are nice and large unlike the selenoids on the NOS kits which are tiny in that shot range and basically pathetic.
Hardest part is finding a good spot to mount the selenoids anyways. I'll enclose a pic of where I mounted mine. Best spot I could find.
Hope this wasnt too winded.
Ben...