I trust MSI and Sapphire for their products, Sapphire provide excellent support also.
256MB memory on graphics cards is usually slower than 128MB. If you are buying the latest card then I would get 256MB memory because it comes as standard these days and is usually better than 128MB.
Something like the 256MB Hercules 9800XT would be nice.
[size=0.5]Full Aluminium ThermalTake Case
AMD Athlon XP 3200+ *400 FSB* Barton (2.2GHz)
ThermalTake Volcano 11+ Xaser Edition Air Cooling
1024MB Corsair TwinX XMS 3200 (Dual Channel 2x512) 2-3-2-6
256Mb XFX 7800 GS EXTREME
2x WD Raptors (10krpm 8MB Cache) 36.7GB using RAID -0
Video Logic SonicXplosion 5.1 Soundcard[/size]