Carefull about cheap 400W power supplies, which can't output more than a good 300W power supply and have a high failure rate.
I'd suggest you look at cases from Inwin, Enlight, and Aopen. The older style Inwin and Enlight cases are very sturdy, newer styles of those and the Aopen are middleweights, all 3 companies offer mid-quality power supplies (included in certain models).
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