bad, bad psu in those cases. I wouldn't trust either for a second. I'll suggest getting a Xigmatek Asgard II case and a Corsair CX500 500W PSU instead.
you should be able to run WOW just fine with that CPU.
I'd suggest paying an extra $1.00 for get a 2x2GB kit, dual channel will see a 5% increase.
For GPU, I'd suggest a HD 6870 or GTX 560, both run about $180 +/- $5