18" Bending brake. <-- cheapest price for this basic model, which is the one I have. They also come in 40" width if you want to be able to make whole PC cases. Make sure you have plenty of C-clamps: At least two 3" ones to affix the brake to the worktop (unless you have enough space to bolt it down permanently), and four 2" clamps to keep the top bar pressed down on the work piece. You can pick those up dirt cheap in sets at Wilko or any place like that. You also need an engineer's square or combination square to make sure that the sheet you wish to bend is aligned, well, square. I score the sheet along the line I wish to fold it for a sharper grease. I do this with a 90° angle countersink drill used as a milling bit, in this case cutting a groove to a depth of 0.5mm in the 1.5mm brass sheet.