On the screen protection front try an N900 specific invisi-shield @ around £15. It gets the thumbs up from here.

Make sure you apply carefully & debris free as per the instructions though as there's only one protector in the packet.

If however you buy their universal protector there's two in the packet so one balls up when applying it aint a big deal. Saying that you'll need to make screen template and cut the protector to suit.