Consoles only come with a controller so the PC budget would only include a keyboard and mouse. $400 is more than enough to out spec a console, the OS and console size case is where you'll end up going over budget lol.
Is that a side window panel? Those are scarce on small itx cases, me likey.
This would look very good in bead blasting for the aluminum, black tempered glass assuming that is indeed a window and matte black textured for the 3D printed parts.
I love the design but I'd probably need a hat or something for the top lol, multiple cables and antennas will probably look terrible sticking through the top.
Just checked out your suggestions, Firewolfy's definitely looks promising my ideal sfx case tbh. I might have to settle for the Dan A4 and switch over whenever the MI-6 comes out.
They seem rather scarce, everyone is opting for nano psu when entering sub 7 liter territory. The few out there lack expansion slots, I'll probably just end up modding one of those if I can't find any though.