Need Help Need material selection help for detailed logo

Hello All,

I am working on a 4'x8' outdoor sign. The logo in the attached picture is supposed to sit proud of the background by roughly 1/2". For scale, the 2 horizontal bars on either side are .5" tall and 21" long. The logo has 3 different colors that need to be painted. The background of the sign will be 1" thick HDU. Some of the detail in the tree gets down to only 1/8" wide in some spots. What would be the best material to use for this logo that can then be applied to the HDU?

I wanted to avoid starting out with 1-1/2" thick HDU and routing away that much material. My original idea was to cut the logo out of 1/2" thick HDU and mount it into a mating 1/16" deep pocket. My only concern with that was preventing the fine details from breaking before I get them glued into place. Other ideas were to use MDO or Extira. PVC and acrylic are options also, but I have no experience with them and the painting and bonding makes me nervous. I need this sign to last outdoors for 10 years.