Here is what i hope is a helpful guide about installing a JDM CRX Front End on your USDM CRX (and only CRX, the EF9 Front End is different)
Here are the parts required for a SiR Front (EF8) Conversion:
SiR hood
SiR headlamps
Front Bumper cover
Bumper lights
*YOU DO NOT NEED THE JDM FENDERS, CORNER LIGHTS, OR RAD SUPPORT*
The USDM and JDM fenders fit the same, the corner lights are the same (except for clear to amber) and unlike what most people tell you, the rad support is not the magic fix for this install. most rad supports come with an EF8 kit, but its not shaped any different than the USDM. the only difference is the hole for where the OEM intake went.
here is my How-To on this install
EF8 Hood Latch install
SiR hood has larger openings for the SiR headlights, which are wider than USDM. the bumper cover also has the larger openings for the wider SiR headlamps. and the JDM bumper lights wrap around the sides, unlike USDM.
Also, this is install is only for the SiR parts. ZC parts are also different.
I will post more info as I obtain it or as you have more questions