What Media For Backlit Panels?

[Splattgraphics]

Being new to wide format, I'm not sure what clear or translucent white media and overlam would be right for long-term exterior polycarbonate faces on light boxes. I run a roland XC54 with ecosolvent inks, so the other question would be do I change any settings for backlit prints like this?

 

[printhog]

http://multimedia.3m.com/mws/media/49875O/4-26-making-backlit-sign-faces-all-imaging-methods.pdf