Really seem to be splitting hairs with the motherboards, they are both good brands and pretty comparable stats. Gigabyte might edge out the MSI only because the BIOS [and I'm learning this just from reading the reviews] have limited options. It's only a big deal if you ever want to overclock it. I'm running a reasonably similar Gigabyte, I've had it for probably 2 years now and haven't had any problems. BIOS has enough to it to satisfy my OCing needs, but I don't get very serious with it.
RAM looks good, if it were me I'd pay the extra money for Corsair, but that's just brand name and bling. http://www.newegg.com/Product/Produc...82E16820145345
You MIGHT consider looking into DDR3 2400 but that pretty much doubles the price.
Cases I really have limited knowledge and little opinion. I've always had a spare tower somewhere so I've never had to buy one. Just be sure the power supply you are looking at will fit. I'm using an old Gateway tower now because my Gigabyte board wouldn't fit in my old tower, and the new power supply I'm using is to big to fit... frustrating. Cooler Master is a reputable brand, and it does look cool.