Confused about ATI x700 Pro 256mb AGP running Oblivion

[Stickspoon]

Hi guys,
I'm really confused and could use some good advice. I recently switched to an ATI X700 Pro AGP 256mb and I'm looking forward to Oblivion (elder scrolls IV). What I am confused about is someone told me I could upgrade to the ATI X1300 (I realize its a PCI-E card but if I upgraded I'm going to upgrade my MOBO and processor as well) but I just checked Tom's hardware guide and it looks like the ATI X1300 fares worse than the ATI x700 PRO. So..
1. Which one is actually better?
2. Is there a better card that would be mid-range and worth upgrading to? (I prefer ATI or equivalents like sapphires)
3. Should I need to get a new mother board and processor, what would be good mid range items to get? I heard athlons are really good? (Right now I'm running p4 1.7ghz)
Thanks to all you computer savvy people out there!
Kit

[jdmakkord]

If you want to stay with agp, pick up a sapphire x800GTO 256mb. Great card for the money, I run mine on full detail, and no problems playing bf2 at all.