1. If you are planning to overclock, might as well add a cooler, a hyper 212 will do. If not, then drop the k on the cpu and change the board to h77.
2. I would find a ram with 1600 Mhz and maybe a dual ram (2sticks of 4).
3. If you won't get an ssd, might as well upgrade the Hard drive to caviar black if you have budget.
4. Any of the case will do, but if you'll give me a choice, ill go with the HAF.
5. For the PSU, check this out, http://www.eggxpert.com/forums/permalink/323050/323050/ShowThread.aspx#323050,
you'll see that modxstream is on tier 3 because of temp I suppose. If you can get a better PSU, a Seasonic or Corsair, better change it.