Suggestions dry erase

A customer has asked us to print a wall mural and have a dry erase / anti graffiti finish. I have been using 3m 40c-20r & Vandal Guard for years on smaller projects, but nothing with seams. I'm looking for somebody that has had a similar request for a wall wrap and what worked for them.

 

The wall size would be 8'h x 23'w. I was thinking about a butt seam on the panels, but the print film and laminate would draw up over time. I haven't located a cast dry erase laminate.