For a gaming rig and for the $$: too cpu/mobo heavy and too lite in the h/w that matters the most i.e a GPU with as much teeth your budget allows u and a dependable 80+ PSU powering rig up for 24/7 peace of mind ops ^^
That older Coolermaster PSU is crappy. You want one that has full range active PFC (no little voltage switch) and 80+ certification. Antec, Corsair, Seasonic, and Enermax are among the quality brands. You'll only need 450W-500W with that system.
no i wouldnt have gone for an i3 if i was you, games are starting to utilize four cores now, so IMO i wouldnt go for dual cores unless you are on a really budget build, i would of gone for an amd build if i was you and tried to go for a 5850, then you would have had a good upgrade path as socket am3 will support the upcoming bulldozer cpus