Same engine as mine, just mines cleaner
I really wouldn't bother fitting a k&n. Reasons for this is:
1, you have to buy the kit from k&n as it requires a plate to hold the throttle body down, because with out the air box on top it moves about.
2, Tried a cone filter on the end of the box with out filter in box and not much change in engine note.
3, I believe its around £90 for the k&n kit and you would get so much heat soak from the engine, because the filter attaches on top of the throttle body.
Pointless if you like to have a good mpg figure and also if you like to loss power.
Hopes this helps, you you do decide to get one post pics up.