USB 3.0? Why do you need a fan on the back-plate? Sounds like you could just cut a hole for a fan on the back if you want it. The reason most cases don't have that is because they don't need it, at all, no one does.
Not sure if I could cut a hole in the HAF-X since it has that stamped pattern to give more room behind the mobo tray for cables. I have thought of it though, can't really make a decision without seeing the actual case first hand.
I didn't mention anything about USB 3.0. I'm looking (for example) for the USBs to be vertical or diagonal when plugged in
There are plenty of cases to fit anyone's needs/wants. But my question is do you know a side fan can have negative effects? I'm just trying to make sure you are getting the best possible solution. Just to name a couple I know of, cm 690 II, storm scout, storm sniper, rosewill thor, in win dragon rider, corsair 600t. I didn't mention any with a side window even though the haf x has a window but I'm just not a fan of a window. And then of course there are cases with upward facing usb without a side fan. A look at newegg gets a lot of cases with those 2 criteria. Almost forgot to mention a side fan over the cpu may also limit what hsf you can get.