to build a pc completely from scratch is a very tough thing to do
iv had some experience bending metal and cutting it for various projects and its not what id class as the nicest of materials to work with at home... not too bad with professional equipment but with a dremel and a hammer you will always struggle to get a good finish if building from scratch
iv seen plenty of nice cases destroyed by a dremel and a hammer as even just cutting fan holes is far from easy and can go disastrously wrong
bending metal is a definitely something to avoid without the correct tools... a hammer is definitely the wrong tool
good luck with your project but personally cant justify the cost or the time that would be required to get even a mediocre looking case
could get a silverstone case for the kind of cash this will probably cost which would also accommodate a better motherboard
if i was tempted to build a case id definitely get a removable motherboard tray as cutting around the holes for pci cards and lining everything up would turn into a very time consuming disaster
also doubt id work with metal... possibly 6 square metal sheets and knock together a mountain mod ufo clone.. although if i wanted one of them id probably just buy it