upgrading the computer

Alright, I want to upgrade my computer once again. It is that time. My main problem is my motherboard, it is ancient. My graphics card is a AGP that can run at 8 but motherboard can only support 4. So, that is a problem right there, I cannot use my graphics card to the fullest (ATI Radeon 9600). So, I want a new motherboard but my processor socket is 478. So, if I was to get a new motherboard that was able to support 8X AGP and was 478, thats peachy BUT, I want the comfort of being able to use a PCI-E whenever I have the need to.

Now, I have always have an Intel all my life, but if it is better, I might go for AMD.

INTEL
    http://www.newegg.com/Product/Product.asp?Item=N82E16813123249
    http://www.newegg.com/Product/Product.asp?Item=N82E16819116197
AMD
    http://www.newegg.com/Product/Product.asp?Item=N82E16819103539
    http://www.newegg.com/Product/Product.asp?Item=N82E16813157081

I am running DDRs I am pretty sure. 2 512 rams and my processor is 2.5 pentium 4.
Would one of those pair work flawlessly adopting with the other pieces of equipment? (the ram blah blah) and is the ugrade worth the money? Which one is better?

it will work at reduced performance when running AGP4x as opposed to 8x, obviously, but not as much as like 50% reduced, but more like maybe 10% or less reduced performance, depending on how graphics intensive whatever you do is. Buying a new motherboard for the 478 pentium is not really worth it. Rather a new graphics card for AGP or maybe new processor and motherboard combo with PCI-E support.