I came across a seller on Ebay offering customised perforated sheets in aluminium or stainless steel. I needed a top panel for the chassis of my Sony VFET project so I send them a dxf file and they supplied the panel pictured below for a cost of just £23. The top of the panel is still covered with a plastic film in the picture. The bottom is exposed and has some scratches but they'll not be visible. The holes are very crisp but the edges will need a bit of finishing as they've just been deburred by hand.
I contacted them to ask about their other capabilities and got the response from a very helpful chap;
Our website shows mostly round holes on the patterns page but we can also supply square, oval, rectangular and hexagon. If you need something more exotic, we can lasercut to any specific size or shape.
I'll be ordering from them again. Here are links to their Ebay store and website
