Re: Questions about my dell
The Thermaltake PSU isn't bad, but the 12V rail is weak. As long you won't be running both a power hungry CPU and GPU off it, you should be OK though. It should handle a 2600 and an Allendale.
For the case, I used to have the Cooler Master Elite 330, and it was a brilliant cheap case. I think it might be out of your budget though, at around $40. I don't really know of anything else though.
EDIT: I just had an idea. To save money, why don't you run it in an open test bed? That's what I'm doing ATM.
AMD Phenom II X4 955 BE @ 4.0GHz + TU120E lapped - MSI 770-CD45 AM3 - 2x2GB OCZ DDR3 1333MHz - Sapphire HD 4870 - Samsung Spinpoint 500GB 7200RPM 16MB cache HDD - Tagan TG600-BZ Piperock - (Currently open test bed) - Windows Vista Home Premium 64bit.