Ek9 interior fits everywhere, even a EK hatch rollcage fits the EM/ EJ. You will have no problem with the interior.
Front end, Bonnet should mount the same, the Ek and JDM DC2 is the same so i cant see why the EG would be different. To make the 1/4 panels fit you will need to cut just behind the light but IN FRONT of the start of the flare for the wheel. You will see what i mean when you pull the EK radiator support off and put the EG one on and line it all up. Its not overly hard, just time consuming. Best way to do 1/4's is bolt everything up lights, front bar, bonnet, then take the car to panel shop and let them weld the guards up to suite. Unless you know how to seemweld. A situation like this the front end will be a talking point of your car so people will be looking at it, so its better to get the fidely stuff done by someone who knows what they are doing.

