Buying memory and graphics card for my computer

Hi,
I am interested in upgrading my computer. The only thing that I had trouble with my computer is that it is slow, and I think that it is due to the fact that I have an ancient memory and graphics card. My graphics card is GF8500GT 512MB PCIE and memory – 1GB DDR-2 800MHz.
Should I really upgrade it, or is it better to buy a new one? I want the best for my computer and I found OCZ OCZ2RPR10664GK for memory and Palit nVIDIA GeForce 9800GT Super+ 1GB PCIe as a graphics card. This is the technical specifications of my computer as it is now:
 Memory: 1GB DDR-2 800MHz
Processor:E65502.33 1333FSB C2D
Hard Drive: HITACHISATA2 16MB 320G
Graphics Card: GF8500GT 512MB PCIE
Mother Board: MSI P6N-SLIV2 775 1GLAN
So should I buy the memory and graphics card? Will it fit into my computer? And is there a way using both of the memories, the current one and the new one?
Please help,
Ofir.
Answer #1
mixing memory is not a good option and a computer with those specs i see why u would consider getting a new one
i;d rather buy a whole system and put away the old one to someone else who needs it
but its your choice
Answer #2
Depends on what you want to do with it, if your a gamer first of is a memory upgrade and video card. Graphics I recommend AMD 4770. Memory will be your memory of the same brand and model and buy another 3 of them, or you can replace the whole lot.