The VS 450 should be sufficient.
If you haven't already bought it, I'd recommend the Seasonic S12ii 430w, Antec VP450 or the Corsair CX 430V2 over the VS450.
Also, if this is a gaming rig, you should get a much better gpu instead of cpu.
Thank you all for the quick answers. Much appreciate.
Bartholomew, I have already bought all of these. I'm not a hardcore gamer. Will mostly use my PC for using multiple programs at a time - multiple browser windows, Excel, Winamp, Adobe reader etc. and occassionally a light game like Cricket, Soccer etc. and watching videos and HD movies, so I don't think I need a high end graphics card.
Am I absolutely safe with the above PSU, or just marginally safe? If it is well worth it, then I can try to return this PSU to the seller and buy a new one.