If you are really after an effective intake then I'm afraid you'll have to either get rid of the engine cover or chop it to suit.
The main contenders are (in no particular order!!)...
EVOM's intake - great sound if you like it loud - you'll need a dry filter.
ITG intake - See SteveP's fitment thread.
Forge Twintake - See JonnyC's ED30 build thread
DBilas intake - This is a twist on the panel filter intake with the filter at the leading edge of the intake from the front grille.
All claim good power increases over a panel filter.
As to which is best is very subjective.
HTH