Halo weapons - as long as they're not generic machine guns/rifles/whatever, sure!
Halo helmet - I just plain don't see a point to this
Army caps - see halo helmet
Race cars - an F1 car would be VERY cool
Teddy bears - see halo helmet
Looking through that post gave me some ideas too:
Human-scale plane map (fighter jet? whatever)
Player-scale boat map (an aircraft carrier'd be neat)
Ball-style sandbag (so you can attack it, launch it, whatever)