I like all of the above suggestions. I like msi, unfortunately they haven't done well with the 800 series chipsets for whatever reason. I have noticed a treand on newegg reviews for DOA boards and early failures. I would be cautious.
I can attest to the fact that the samsung F3 500GB are very fast hard drives. I've installed half a dozen over the last year and they are great to work with. However I have seen the F4 1TB going for $80 recently, and I would consider making room in the budget for that.
Also while the 450W may be sufficient, it won't run at its greatest efficiency at full load. You could look at the 500 W models from Corsair or Antec for a little headroom, or step up to a 600-650 W for future upgrades. Antec EA650 is a good one, or the TP 650new. I like modular supplies, but with corsair you definitely pay for modular.
Again if you can afford it for $10 more you could upgrade to the Samsung spinpoint F3 1TB 32MB Cache http://www.newegg.com/Product/Product.aspx?Item=N82E168...
PSU (is this enough?)
Like previously mentioned I would go with the Corsair or Antec 650. I went with the Antec 650 because it was cheaper. But you can't go wrong with either.