ive posted alot about the 6600 gt..my specs 512 mb ram..1.8 ghz processor..and 250 watt power supply..will this card work

http://www.amazon.com/exec/obidos/tg/detail/-/B0006VHVI2/qid=1117657146/sr=8-3/ref=pd_csp_3/104-8124504-8956746?v=glance&s=electronics&n=507846

or this one

http://www.amazon.com/exec/obidos/tg/detail/-/B0002MW018/qid=1117657333/sr=8-2/ref=pd_csp_2/104-8124504-8956746?v=glance&s=electronics&n=507846