Welcome, and congrats! You will find this forum to be quite welcoming and informative. It is truly a great community, and a great asset and resource as well.
There are a few EK9s within the States that have been here for a while. I knew of at least four from back in 2010-2015. I've been out of touch and haven't kept tabs since then really. Still quite rare though. And parts definitely are difficult to find here. H-motors online and ICB Motorsports are the main parts sources but still they are fairly limited. The UK and Japan are usually your best bets.
Also, JDM ECUs do not monitor the Vtec oil pressure, so no harness for it is normal. ECU part numbers will vary depending on the year and specifics.
Btw, the resource area here is a great source, this thread has a lot of the OEM part numbers for more common parts:
Im sick & tired of trying to find parts numbers I know il get the just go down to honda replys But my local honda is run by monkeys &takes them about half an hour to find a part number:nono: And the other reason Im doing this is beause i order all my honda parts from Lings Honda online but u...
www.ek9.org
Another great resource for part numbers is jp-carparts.com. I use them to look up part numbers then cross reference/search with USDM Honda websites. Here's their Civic 3 door hatchback list:
https://jp-carparts.com/honda/cartypelist.php?maker=honda&type=CIVIC 3D
Always check multiple sources before ordering parts, especially new OEM Honda parts. Even when US Honda dealers have the parts they are often times more expensive than getting them shipped from the UK or Japan.
What year is yours? And what parts are you needing? Photos would be great as well.