The Aspire case you selected includes a 450 watt powwr supply - they have versions a vailable with 500 w as well. While the 600w enermax PS you have added is a great choice, it is overkill for you here.
Thanks, Gary! I really appreciate the help on these boards.
I know the 600w is overkill, but after suffering two ps blowouts on my current PC (one resulting in the loss of my sound card and boot drive), I wanted to settle on a nice one with more than enough juice to run the whole system. I used a chart that showed recommended wattage per component and estimated a high 550w need. With 600w, I don't have to worry at all. It sucks to shell out so much for it but it's worth it to me just for peace of mind. And, I have room to expand.