Solvent welding acrylic with methylene chloride works really well, with a couple of caveats. The first of course is that methylene chloride is very dangerous and you want to work with it under a Plymovent or in a fume hood or outside. It also has zero gap filling ability so butted joints have to be precise and you want machined edges, though a well set up router or really good panel saw cut will work. To give you an idea, there is usually about .003" taper in a waterjet cut and this is too much gap to fill. Ask me how I know. You also need a way to hold the pieces while gluing so that you just fill the joint and don't have it separate and then freeze. I imagine there must be acrylic specific adhesives that have a little more gap filling ability and longer working time and are less toxic. Solvent welding is definitely the best way to make a really nice box, though I'd still go to a bit thicker material, like 3/16" to make the gluing easier.
Heat bending acrylic also works nicely and you can get pretty accurate bends since they are averaged over the entire length of the heated area. You could readily bend a strip into a box, but the top wouldn't be perfect, so you'd have to have some overlap on your hinged lid. Polycabonrate can indeed be bent in a press brake but going all the way to 90 degrees is pushing it at least for anything thicker than .125". It tends to want to relax too, which might cause a box to distort. It can also be solvent welded with methylene chloride but the results just aren't as good as acrylic. We like using polycarbonate in 8020 frames but they only make sense when you're making enclosures or screens on the order over several feet in typical lengths.