The reason for good air flow seen there besides a gaming case often seeing a larger supply is the extra cooling offered for hard drives by way of having two large front intake fans instead of one. When putting the current build together with the old case the board saw higher temps then the cpu! 48C
That old Socket A top and rear 80mm pair of fans non-vented case had to go! The AeroCool model here with a 140mm front, 120 rear, and two 120s on the side cover saw the board temps drop to 31C fast. Even the Zalman 9500 or any other cooler wouldn't bring the cpu temps 44-46C down if the board is hot. Once the air flow saw a large increase the ambient temps inside the case dropped sharply.
The 900 offers two 120s over one 140 in use now for the front plus the 200mm top fan. Since the case here slides into a cabinet where the front faces out and not much air flow along the sides while seeing plenty of room above the case the Antec model works here.