The Antec Twelve Hundred is not a beauty queen.
It's primary function is cooling and it excels at that. It's not silent either.
Reviews:
http://www.hexus.net/content/item.php?item=12726&page=1
http://www.hardwarelogic.com/news/135/ARTICLE/4078/2/2008-08-04.html
http://www.extremetech.com/article2/0,2845,2304827,00.asp
Your configuration is very simple (a standard pc) so I wouldn't really bother with a $200 case.
I think a good $100 case like the CM RC-690 or Antec Nine Hundred would serve you just as well (room for upto 4 harddrives and 2 optical drives). The HD 4870 is not dependant on high case airflow as it dumps the heat outside the case. All it needs is a front 120mm intake for fresh air.