https://www.rx7club.com/single-turbo-rx-7s-23/single-question-426637/

 

1) yes, if you don't spend the money and upgrade your injectors now...you can run the break-in period with 550cc primary injectors and tear your car down again and upgrade when ready. You won't be able to support much boost with the 850cc secondaries...so, if you want to waste your time, go ahead. Is 9psi okay with the stock fuel set-up and better pump? I have no idea...if you have an adjustable FPR, you can run higher fuel pressure to squeeze more fuel out, the side feed injectors are fine running 100% all day long...I'd personnally have them sent out to RC engineering for flow testing before I did that. Then step boost up with a wideband O2 and see if you can get to 9psi. Why waste time and money prepping the stock fuel set-up for a single?
You can even run break in with the stock IC...again, way waste effort and money to make a single work with it, I dunno.

2) things you are missing...I'm sure a bunch of ****. Putting a kit together yourself is a lot of work. I didn't see turbo oil feed or return line on your list; no FPR, intake, vacuum lines, plus all the little ****: couplers, o-rings, clamps, block off plates, vacuum caps, loop lines.

Good Luck and Have fun