One, that case pwns! I love the X-Navigator case. But, it should come with a 500Watt PSU! That PSU is plenty! Get that Case! It has 5 system fans as well!
About the video card. This is AGP, so I will give you the best option right now from both nVidia and ATi ok? Your choice. Links below!
http://www.newegg.com/app/ViewProductDesc.asp?description=14-127-127&depa=1
This is a Radeon 9800Pro from MCI. It is right on the verge of $200, and iis a fairly decent card. Its clock rates are slow!
http://www.newegg.com/app/ViewProductDesc.asp?description=14-150-066&depa=1
This is an XFX card that has good reviews, and is very fast, plus is bit cheaper! I'd go nVidia here, the 5900Ultra pwns!