Nice case choice! But do you really want to put a $130 CPU into a $170 case?
Nice HSF choice @ $90. The CoolerMaster Real Power Pro 650W PSU is an OK choice for someone on a tight budget @ $70 after rebate.
High end Case and HSF. Budget CPU and PSU. Is there something you're not telling us?
What overall budget are you working with?
Scrimp for now if you must, but one thing you should never scrimp on is the PSU. It is the single most important component of your build. I've heard of underpowered or cheap PSU's frying and taking out other parts of the build. Not good. For the best PSU's money can buy, you can't go wrong with Corsair.
I don't think the CM Real Power Pro 650w PSU falls into the "avoid at all costs" category. It's a fair choice for a gaming build on a tight budget. It also has 8-pin PCI-e connectors which is a nice choice.
Have you looked at the CM RC-690 case? Its $45 after rebates or $125 less than the Cosmos 1000 and its had decent reviews RC 690 review.
For other ideas on other system components check this AMD Mid-Range Gaming guide. You'll note they DO recommend the X2 5000 Black Edition but then they're not using it as a place holder for a Phenom. An upgrade from the 8800GTS to 8800GT is worth the short wait while the release prices stablize.
Phenom's are drop in compatible with AM2 motherboards at HyperTransport 2 bus speeds while socket AM2+ motherboards will offer HyperTransport 3 bus speeds
If you want to upgrade the PSU a bit you can't go wrong with the Corsair HX 520