Please don't kick the topic so quickly.
EK4 exhaust will fit with EK4 manifold and EK4 decat, cat or sports cat. EK4 exhaust will not fit on EK3 exhaust manifold, maybe with a decat added but not sure about that. EK4 induction will only fit with customization I think.
If you want to know what to go for, have a search on Google and other boards. Search for something like "Civic VTI which intake" or something like that.
Besides searching on Google you could take a look in some shops to see what they've got for your car, like VTECDirect or other traders that can be found on this board. Or take a look at project topics here on this board.
Then, when you've found a product you can search for something like "product x review" or "product x power gains" to see how good they are. It's also worth a look at the topics on top of the air intake/exhaust sub-board that are sticky.
There are so many options and some effort from your side to search for options would be highly appreciated! If you do a little research yourself and let me know what you've found, I'll be happy to help you with any questions!