Niko,
Let me know what you come up with on the airbox, would like to drop the weight as well.
There's a guy on ty4stroke who used a rubbermaid bread box to make his own intake, but I don't like that solution, seems poor on airflow and durability.
Also, if it allows access to the battery, you could drop the extra jumper wiring which runs to the right side of the sled. It would probably save a pound, that wire is fairly thick.
In my case i'm going to put a connector on the battery for trickle charging, so access to the battery would be a nice plus. It's easier to take off the hood than the side panel.
BTW, if you're in tahoe this year we should go riding.
-Mark