Is there an aftermarket company that makes a decent nismo/aero front bumper for a 03 04 sedan. I can find oem bumpers but cant find the lisence plate cover.

I used to know of a few but I don't know now if they are still in business or are making the bumpers any more. You'll probably get a better response to your question in a day or 2 here but poke through the vendors in the Vendor classified section and look for the bumpers there or you might even scour ebay to see what they have if you haven't already.