Dull question...

Jesus. I'm even bored by asking this question, but I'll give it a go anyway, even though I know the answer I think...
System (in a nutshell & not too 'techy'):
1.5g decent ram
Radeon X800 GTO (AGP) card
AthlonXP 2700+
Loads of space on my Hard Drive (decent HD and brand new)
Firstly...
In the quest for better frame rates (currently getting 25-35 FPS on high settings), is it my processor that's holding back the rest of my system?
Secondly...
I'm tempted to buy a new processor and motherboard. I want a mother board that's AMD compatible ('coz I'm gonna by one of those shiny 64 bit fuckers), but also with AGP and PCI-E slots. I've only just bought my X800 AGP and I'm not ready to buy another card yet, but I will one day and so I want to have the PCI-E option for when I need it. What motherboard should I get - is this one I found OK?
System (in a nutshell & not too 'techy'):
1.5g decent ram
Radeon X800 GTO (AGP) card
AthlonXP 2700+
Loads of space on my Hard Drive (decent HD and brand new)
Firstly...
In the quest for better frame rates (currently getting 25-35 FPS on high settings), is it my processor that's holding back the rest of my system?
Secondly...
I'm tempted to buy a new processor and motherboard. I want a mother board that's AMD compatible ('coz I'm gonna by one of those shiny 64 bit fuckers), but also with AGP and PCI-E slots. I've only just bought my X800 AGP and I'm not ready to buy another card yet, but I will one day and so I want to have the PCI-E option for when I need it. What motherboard should I get - is this one I found OK?