CPU/Motherboard/Fan/PSU Recommendations

I just received a computer for free from someone they don't need it anymore. Right now I have two computers at home. I am planning to make one computer just for word processing, therefore I am giving all the junk parts to that computer.

Computer A
CPU Type Intel Pentium 4 530J, 3000 MHz (15 x 200)
Motherboard Name Intel Avalon D915GAV (4 PCI, 2 PCI-E x1, 1 PCI-E x16, 4 DDR DIMM, Audio, Video, LAN)
http://www.intel.com/products/motherboard/D915GAV/index.htm
Motherboard Chipset Intel Grantsdale-G i915G
System Memory 1504 MB (PC3200 DDR SDRAM)
DIMM 1: Kingston K
DIMM 2: Elpida EBD52UC8AMFA-5B
DIMM 3: Empty
DIMM 4: Elpida EBD52UC8AMFA-5B

Computer B
CPU Type Intel Pentium 4 630, 3000 MHz (15 x 200)
Motherboard Name Foxconn 915M03-G/915M07-G <-- ?? I can't find links for this product.
Motherboard Chipset Intel Grantsdale-G i915GL
System Memory 503 MB (PC3200 DDR SDRAM)
DIMM 1: Random Ram

My Questions are
1) Which CPU is better? I am guessing Pentium 4 630, 3000 MHz (15 x 200)
2) Which Motherboard is better?
3) Computer A, Does that 512 Kingston even make a difference? If not I am going give it to Computer B
4) Did I put the Dual RAM in the wrong slots? 1&2 or 1&3?
5) Will this video card work on any of my computers A/B? I am using onboard video card at the moment. I am a casual gamer (warcraft 3, waiting for starcraft 2 ) and I find it pretty bad, slow choppy.
http://www.canadacomputers.com/index.php?do=ShowProduct&cmd=pd&pid=009601&cid=999.243.390
6) Also I am thinking of buying a new power supply and fan links below (good choice?), they fit in any standard cases, right? because I have one big tower ugly and a smaller tower. Sorry, I don't know much on the topic.
http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=2974309&CatId=1483
Planning on getting another harddrive and maybe that new video card, 600W a little too much?
http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=1800601&CatId=493

Thanks in advance, hiyooo