Inspiron 620 upgrade

Lets get right to the point.i want a new video card for my computer.I have a dell Inspiron 620, 300 watts for psu ,1920/1080. I have upgrades right now . I was thinking about getting the GeForce gt 630 which is 300 watts which they claim. If you can help me find one that has good specs and highest directx as possible and can work with my computer at a budget of 100 . It will mean so much too me thank you I was also thinking about getting this : http://www.newegg.com/Product/Product.aspx?Item=N82E16814102988 And this : http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=A6173020&mfgpid=223685&chassisid=8560 Well please look at them and see if there good if not recommend me one that is about the best one I can get