You might want a little more clearance between your PSU and HDDs. Otherwise this looks very nice so far.-
That's definately an easier way to make a backplate, all you'd need is a flat sheet of material with the appropriate holes cut, then the PCI mounts bent outwards.
i think the middle one looks the best. But how about a combination between the middle one and the last one! ill edit one of your drawings with what i mean. Edit: Here you go...
That front design looks really nice, but I'd like to suggest something. You're not going to get great airflow through that. You've got a lot of space chewed up because of aesthetics. As was mentioned earlier you need to space our your HD's and the PS as well. Why don't you move your HD's behind your design, and instead of placing the fans there put them in the removable side panel? You could use a couple spring connectors from http://mouser.com so you could take the panel off without having to unhook wires. I think that Bill from www.mnpctech.com is going to be offering a acrylic window that is already pre cut to accept 4 120mm fans in the very near future. I think your design and idea are awesome so don't think I'm knocking you in the slightest. You're off to a great start and I can't wait to see the work log! Take it easy, Keith
are you going to have any cards other than a graphics card? cause depending on the layout of the board, you could get the power supply dropped down to cover some of the motherboard, cutting down the height some more
from what i know, with average hardware (not like i7, gtx280 type things) the new fan idea would work. Also, if you wanted to make the front more interesting, you could make it a double front, one with grills, vents, and stuff, then acrylic and lighting before the components. Don't know how minimal you want it though...
From looking at your new design, make sure you add legs to it so the bottom fan can get air. Also the longest gfx card on the market at the moment is the 4850X2 @ 12.5" long. just to give you a max spec.
Looks good but i reckon you still need more room between the psu and the HDDs to let the cables out! Might be an idea getting the psu you're using and working out the maximum sensible bend you can use... RwD