couple of rudimentary videocard questions (ive tried searching 8)

and maybee i just suck at it!

situation, im trying to get a dual monitor system up and running on my computer
for the purpose of running cubase (music software) on 2 screens.

atm my computer is a duron 900mhz 'spitfire(?)' with an Asustek A7VK-133 motherboard.

the AGP slot info says:
AGP 4x
data bus width: 32bit
provides 5.0volts
provides 3.3volts (doesnt say anything else)

so after all that my questions are:
1. can i get a dual head agp card like a radeon 9200 and above (with a 64-128 ddr sdram supported bus) into my computer?
2. is there anything i should really know about voltage supplied to the card?
3. my computer is running sdram as its memory and the motherboard says
'other, dimm, sdram' supported. will it then make a difference if i get a video card running ddr?

thanks a lot for any help people, im pretty new to this game and constantly and but im trying SO hard harhar