Also, get this DVD burner:
LITE-ON Black 16X DVD+R 8X DVD+RW 4X DVD+R DL 16X DVD-R 6X DVD-RW 16X DVD-ROM 48X CD-R 24X CD-RW 48X CD-ROM 2M Cache IDE DVD Burner - Retail
Retail comes with Nero burning software so you can burn CDs and DVDs. It's black to match that case you picked above. You may need a floppy drive too. Anyone will do. They are so generic these days. The motherboard will include a floppy cable and hard drive cable for your Seagate drive too.
As for the black case, I feel this is a nice one for the price. You can save some money there if you get this:
ASPIRE X-Dreamer ATXB3KLW-BK/420W Black Steel ATX Mid Tower Computer Case ATX 420W power supply for AMD/Intel Power Supply - Retail
It's got a bigger power supply than the one you picked out and so much cheaper too.