Have to disappoint you but there is only 2 ways of lasershows. You build your gear yourself or you buy already premade. There is no middle people. To make cases you need to design it yourself or get someone to design and bring those blueprints to a machine shop. 12X24X12... I really doubt it will fit in there. Because if you will balance your Green the you will need a very powerfull lasers. Laser heads will fit but power supplys.... no
I hired an Italian guy to do my wires. Now they look like spaghetti!