No need for injectors, at least I haven't found the need...yet. I'm running 7psi with the stock injectors at the moment and haven't hear my engine ping at all even at the rev limiter. Mind you though, I have an adjustable vortech fuel pressure regulator in place so that could also be why. The FPR doesn't cost very much, roughly under $200 CDN.
Piping will depend on what you want, but a steel 2.5" mandrel U-Bend costs $25 a piece from the shop I go to, and I just hacksaw the suckers into the segments and shapes I need. You can avoid welding (mostly) by using rienforced silicone couplings, so it's all good, but the couplings aren't cheap at $20 a piece
(you can't use the type you're used to seeing with cold-air-intakes unless they're rienforced (have a threaded mesh in the rubber) otherwise the coupling will blow up on you.
I'd say, if you deleted the intercooler, you would need:
1x fuel pressure regulator $200 CDN (more or less)
1x 2.5" mandrel u-bend $25 CDN (for the blower outlet)
1x 3.0" mandrel u-bend $25 CDN (for the blower inlet)
2x 90' silicone rienforced elbow $12 ~ 30 USD each (get em off ebay)
2x 2.5" silicone rienforced couplings $20 CDN each
10x T-Bolt clamps, or regular hose clamps (but you risk leaking air) $1.39 ~ $4 CDN each
1x piggy back system (smt-6 like I have, $550 CDN), or custom tuned chip by MarkD or someone else ($$$).
As well, someone (like myself
) would need to weld a spout on one of the pipes for your idle control valve to breath through.
that's about it, for your basic stage 1 setup, but expect some downtime because there will always be unforseen problems (trust me).