Without opening the engine to raise compression stage 2 cams will not perform well on a b16b.
I would not recommend a 70mm TB or S2 intake(assuming pro series which is almost identical to the type r intake). A Toda style 4-2-1 exhaust manifold coupled to a 2.5" decat and catback and then a...
If that is the picture of your current wiring harness from the D16Y8 it would seem your car is OBD2A wiring, in which case the PCT Ecu should plug straight in.
The best option is always a custom tuned Ecu. I believe I done a back to back test of Spoon Ecu vs Custom tuned obd1 Ecu some time ago, can't remember if I posted in on here or not - will try locate it.
I've setup 24XX cams on a b18c with Wiseco 12.5:1 pistons and there was no issues with clearance. Providing the cams are degreed correctly and Ecu tuned correctly it will idle nice and smooth.
A higher static compression will yield more HP per PSI of boost than the lower CR engine. If you are in the UK and plan to use the likes of Shell V power(99 octane) then for sure build the motor to 10.0:1 CR.
We tune Link Ecu's on all different kind of cars weekly, very good Ecu's.
Your 550cc injectors will be good as maxed out at 400bhp so best to upgrade. I suggest you go with Bosch EV14 style injectors, i.e Grams 750cc, ID725 etc...
I am certainly not as active as I once used to be on here, or any other forum for that matter. Unfortunately work tends to consume most my time nowadays. Nice to see some old user names that I recognize still posting on here.