in my opinion you did everything backwards.... the first thing you need is the motherboard.
the good news is, you need to tigerdirect.com search motherboards that support am3 socket, and ddr3 1600
thats easy under 200 bucks
I'd get a bigger power supply, same brand.
I'd also look for a mobo that has 4 240 pin slots and supports 16 ghz under a 64 bit OS 8ghz under 32 bit.
when you're starting from the ground up.... start from the ground up.
The case is always an issue when it comes to this way of buying..... you bought everything backwards (assuming you have this stuff in your closet now)
Cases are built around motherboards.... not the other way around. it's much easier to find a fit when you know the dimensions of the board rather than vise-versa.
In general, you need a mobo that supports:
DDR3 1600 (4 slots) 240 pin I say this because of upgradeability.
Socket AM3 (this is your first search when looking at a motherboard)
dvd, drives (all mobos now are Serial ATA)
PCIE slot (all mobos now have this with with either 2.0, or 2.1)
I'd get a 650w psu for the possibility of upgrade later. Even the highest of high cards out there now require no higher than 500w supply.... but more is better.
Most motherboards also have 4 or more SATA ports, so your cd, HD, and whatever else you might want in it will hookup just fine.
ati, bioware, and gigabyte all have suitable boards available with either 2 slots for ram, 3,4,and 5 slots for SATA, and other goodies like on board graphics assistance (that's where help for games and HD vid comes in) and other things.