I have ONE 5870 for sale. It is an ATI OEM. It is 13.5 inches long. $350 each shipped. Will fit in a Haf 922. They came out of an alienware aurora.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290434829269&ssPageName=STRK:MESELX:IT#ht_500wt_1182
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290434829269&ssPageName=STRK:MESELX:IT#ht_500wt_1182