Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
For the size: Take four optical drives. Stack them in two collumns of two. This is your minimum case size if you want an optical drive, an HDD and your MATX board. Take whatever you have handy to build this case. Plywood, a chopped-up big tower, tupperware, who cares?
Mount your components, of course leaving holes in the appropriate container walls.