Here are my specs: Intel C2D 2.8GHz Mobo Intel DG31PR 4 Gb RAM DDR2 1x250gb seagate HDD 1x1TB seagate HDD I want to upgrade to HD 7770 for gaming purposes Q.1.)Can a Antec VP450W handle the card smoothly? Q.2.)Is the HD 7770 worth the extra buck or should I settle for HD 7750? Q.3)How much difference does the brand make I am thinking between saphire and asus (I heard negative things about gigabyte & xfx). Q.4)Asus card mentions it is factory overclocked how much difference in performance does that make? Thanks.