What vid card to take (I'm clueless)

[Rawis]

I dont have that much brains when it comes to comps I'm currently using
XPS 420 E8500 Core 2 Duo Processor 3.16GHz, 6MB, 1333MHz
D07X414
XPS 420 Resource DVD
English - XPS 420 System Docs (EUR power cord)
Memory 4GB Dual Channel DDR2 800MHz [4x1024MB] Memory

Now I got some Q.
1. Seeying my memory is ddr2 can I go for ddr3 cards ?
2. From this site wich one would be best suited in my case ?
http://www.komplett.nl/k/kl.aspx?bn=10488&mfr=&filter=A03616.K144543.PRICE.50-100.

thanks in advance :3

 

[obsidian86]

graphics card ram has no bearing on system ram
depending on your power supply i know the 420 came with the 425watts and 375 watt power supplies if you got the 425 watt model the 5770 will be fine
get a good 450watt+ if you got tthe 375watt version

http://www.komplett.nl/k/kl.aspx?bn=10488&mfr=&filter=A00247.K186207.A03616.K144544.

 

[Rawis]

Looking for a card around 50-100 range wich do you recommend

 

[obsidian86]

http://www.komplett.nl/k/ki.aspx?sku=449929

http://www.komplett.nl/k/ki.aspx?sku=439020

any of these 2 if you wanna change your power supply or this and keep your power supply

http://www.komplett.nl/k/ki.aspx?sku=490297