VGA stands for "Video Graphics Adapter", is an analog computer display standard first marketed by IBM in 1987. Although the standard VGA is no longer used because it has been replaced by a newer standard, VGA is implemented on the Pocket PC. VGA was the last graphical standard followed by the majority of computer graphics card manufacturer. Display Windows is still using the VGA mode because it is supported by many manufacturers of monitors and graphics cards. for more about VGA Details in here.
Tips For Choosing VGA, you have to know is that first you notice Slot VGA, whether it's AGP or PCI express slot.
Well then, you do not bother to choose "DDR VGA" Because even if your motherboard has slots for VGA DDR 2 but can be used for any DDR RAM memory types used in VGA (GDDR) there is no direct correlation with the type of RAM used on the motherboard. they are both memory (RAM) but the real application of different scope of work. RAM on VGA card just to process the data in the VGA graphics card, while the RAM on the motherboard take to process all the data that is processed by the motherboard (Processor, VGA). So even if your main board will be installed DDR 2 DDR 5 is not a problem.
Furthermore, do not forget to buy the PSU or Power Supply is also a good thing for VGA that you will install, because if its less then it will not turn on, the greater the quality VGA (second number the greater), the greater the power required.