I have been looking at the width dimensions of cases also. The Antec P182 width is only 8.1 inches and reading newegg reviews some people using that case have problems. So now I am looking at Cooler Master Stacker for 239.00 width is over 9 inches, which should be fine but more expensive.
I also read that the mobo's capacitors could get in the way and I read that someone even filed down the side of their non-stock fan for it to fit.