The case I have has a 240W power supply which easily handles my setup below so not sure I agree with the other posters comment. Also, you are unlikely to be stressing out this system if you are only using it for a media centre PC so I doubt the devices are going to be drawing their maximum wattage from the PSU.
Also, I would check the manufacturers website very carefully for which motherboard layouts are compatibile with your case especially if you are planning on using the PCI riser kit that comes with it.
Also, I would check the manufacturers website very carefully for which motherboard layouts are compatibile with your case especially if you are planning on using the PCI riser kit that comes with it.