Interesting topic brought back alive :)
Just share what i know.
On a totally stock B18C or C5, with just ported B16A head, CTR Cams, B18C5 inlet + throttle, exhaust system and rechip ecu, i think most paople can get about 160-170 atw hp.
With B18C/C5 block and B16A head, you can put modded CTR pistons but compression will be very high and above 12:1. If you got no piggy back with upgraded injectors and fuel pump you can forget it, as you will just run lean and engine won't last. Furthermore, with so much compression, its better to run high lift/duration cams to reduce static compression but then car will not be so driveable on street. But a properly tuned, B18C with CTR pistons + aftermarket cams i believe can deliver the 185atw hp.
I heard alot of people use Ford TX3 pistons for street use, but i personally seen a civic last year with TX3 pistons. The car was tuned on dyno for proper a/f and ignition. Car was fast, but after 2 race in a MSS weekend with consistent 9k+rpm, the car started to sound funny a power start dropping. Open up the engine the following day and you see the liner start cracking.
Thats why in USA, you see forge piston manufacturer most of them only make 81mm to 82mm pistons for B16A/B18C then mostly 84mm to 85mm meant for B20B block.
Honda also don't make 1mm overbore. I believe its only 0.25 or 0.50 overbore only.