Well this is a plan for a case that i hope to start building soon. This will be my first build and my first time designing one, so i hope some more experienced people will be able to give me some pointers. I plan on constructing the frame out of aluminium angle and then using sheets of aluminium for the panels. The motherboard tray i plan to make out of acrylic and this will be raised from the base of the case to provide some cable management options. The parts in these images are only used to show the placement of the components but i tried to use similar sized components.
I would say do the mobo tray in metal because of the heat, it might not cause any problems, but I wouldn't like to take the chance. Apart from that is looks like a good design. I like the idea of the water cooling have it's own chamber..Good luck with this one, it'll make an interesting project.
I like the L shape design. Just quietly though, depending on what you plan to water cool, that single radiator may not be big enough..
Looks good, personally I wouldn't put the PSU output so close to the HDD bay, the only real reason is accessibility and how cramped it might get there, but that's just me.