Spreaders are gone over here in Perth... very few boats running them now.
In regards to the Renders, looks pretty, but the devil is in the details as noted above, the scale of the upper struts on the forward wingbars looks out, they seem too small to me. these are compressive members so need to be bigger than a tensile item (otherwise we'd all use rope for these!).
Don't forget the cheese wire at the back. Rear wing bars don't last long without it.
Also the routing of your control lines is an interesting problem on Moths, what sort of cleats are you using for your Vang and downhaul? This can have a major effect on geometry of the front wingbar base and your deck.
I know its a rendering, but rudder foil looks huge...