I'm working on a large sign design (10'w x 12'h). I'm debating on which material to use for the background. Custom prismatic letters, a ribbon plus other carvings will be attached (all HUD). We will use a steel structure behind for support. Will ship-lap panels 3 @ 4x10 stacked on top of each other. What are the major concerns with each material? I'm more familiar with HUD, esp regarding finishing. Not sure of the best way to finish the PVC product. The HUD would normally be primed and painted with exterior latex paints. Is that same paint combo effective on PVC?