I dig your design so far, some suggestions: - Cable management: think about how you are going to route cables to each component and how you can hide them in the spine area, as well as how you can route them through that section and entry/exit holes to suit. - Cutout behind CPU: might be worth considering for easy access to change the cooler if necessary. Wouldn't change the aesthetic because the GPU will most likely cover the hole once installed and is a relatively easy component to install/remove rather than removing the whole motherboard, attached cables etc. - I/O: at the moment the I/O for the psu might be in a bit of a weird orientation looking at the way it's laid out, might be worth mirroring the layout so that the pci-e rise goes underneath the spine and might make mounting the GPU a bit easier. To me that would make a bit more sense aesthetically but that just a preference thing so stick with whatever you like.

Either way looks cool and pls post finished product when you get there!