I can't find any info on the GWS Slow Stik as to wing material, wing loading and ARF/kit . Even Horizon has NO INFO on this.

What exactly do you need to know?

Wing is foam.
Span 46.5"
Wing area 506 square inches
Wing loading 3.4oz/sq in (depending on battery used, I suppose)

Anything else?

Slow Sticks, or almost any park flyer for that matter, would be considered an ARF. And yes, they have an undercambered, thin foam wing.
Dennis-