If you haven't found a shop to fabricate the panels, take a look at
this website www.emachineshop.com. You download their version of
autocad, draw your part, select materials, click, click, pay,
delivery. Three guys here ordered panels to spread out the set-up
cost and I recall it was about $120/each for 3mm aluminum nicely laser
cut. They also have water jet and every other process. I have no
affiliation with this company, just think it's a cool option for
projects.
~Barny