hmmmm. You know you can get hubs for this sort of thing? My mobo came with 2 break out boxes - one for the card slots area, and the other for a 3.5 " bay. You could get any case and easily convert it to have support for as many USB ports as you have headers for on your motherboard.
Thank you for the suggestion, but I already have a USB hub. However, I have more USBs than my hub can hold (they only carry up to 4 before they require a power outlet - which I don't have any more of due to so many things already plugged in).
I suppose I could get another USB hub and plug it in if I have to, but I'd rather get a case that can sustain more of them instead.