Remember that the shroud inside the box is key. What's that thing cost anyways, like $120 for an aluminum shroud and an acrylic heavy duty box?
2 24x48x3/8 pieces of acrylic can be had for $83 from
www.usplastic.com . Then you can make everything out of acrylic, and save $35 as long as you can cut acrylic well and get it right, you save nearly $40. If you do it all out of aluminum, the material is cheaper($50-60), but the cutting is more difficult.