Don't go with a Chaintech mobo, they aren't as good overclocking/stability wise as some of the other brands.
DFI is fine, but you are taking a hit or miss kind of risk. There boards that WORK, are rock solid and overclock well, but alot of people RMA a few times before they get a solid board. That's the way it was for my friends...he got 2 bad ones and finally his 3rd was awesome...did better than my board. I suggest ABIT or ASUS as well, but i imagine the DFI will do fine, assuming it works out of the box like any other board.
If you plan on overclockign alot then that Mushkin won't be the best. It's Value RAM and not known to overclock very high...but i'd say it should hit ~230MHz (i have a kit like that that does 230MHz on an NF2 system) For light overclocking or stock uses it should do jsut fine.
Your case is all you, your preference. BUT the PSU that comes for free with the case is most likely extremely cheap. If it works, then good, you got a PSU. But i would keep ~$100 in your pocket JUST INCASE the included PSU is crap. That's just a precaution though.