dude i have no idea what mobo you have and its definaly time for a new computer. i would start saving and looking around at what to get for a new computer. unless you are just doing internet surfing your system in pretty bad shape.
I would put 3 sticks (1GB x 3) of PC-3200 DDR Ram. total ram 3GB. Win XP will not utilize much more than 3GB. Also, if you put 2 PC-3200 and 1 PC-2700 they all three will run at the lowest sticks speed, in this case PC-2700.
Yes, the video card will work but will probably bottleneck at the CPU.