less than 16" deep (from front to back) or wide as you stated from side to side looking at the front of the case?
if it's matx and less than 16" deep then go for the nmedia 200 - it fits all your requirements and looks very good it's also the only case less than $400 which can fit a full atx power supply while being less than 16" deep.
now if it truly is less than 16" wide you're looking for then you really limit your options. the nmedia 100 and the antec aria will both fit the bill but neither will take a full atx power supply.
this should point you in the right direction at least?
if it's matx and less than 16" deep then go for the nmedia 200 - it fits all your requirements and looks very good it's also the only case less than $400 which can fit a full atx power supply while being less than 16" deep.
now if it truly is less than 16" wide you're looking for then you really limit your options. the nmedia 100 and the antec aria will both fit the bill but neither will take a full atx power supply.
this should point you in the right direction at least?