I have an HP Pavilion Elite e9270f Desktop (http://h20564.www2.hp.com/hpsc/doc/public/display?docId=c01905329) which has ATI Radeon HD4650 graphic card. I'm not an expert when it comes to this stuff but I would like to replace and upgrade my graphic card, I have MSI MS-7613 (Indio) motherboard. Can you give me some recommendations for compatible graphic cards and would I need to replace my power supply too If i upgrade, If yes which one would be compatible as well. I'm looking for something under $100 if possible for graphic card and under $50 for power supply. Thank you!