in india?
DDR 400 is outdated, so if you find it, it will most likely be expensive (more so than the DDR2)
also, I think that mobo (915 chipset) has a PCI-E slot. so any card should do.
But we need more information on your part
From Intels site:
Flexible memory support, for dual-channel DDR2 533/DDR2 400 or DDR400/DDR333 memory, in configurations of up to 4 GB RAM.
So you can get DDR2 533. I would do that rather than get DDR 400
PCI Express* x16 graphics delivers up to 4 GB/s per direction, 3.5 times more bandwidth than AGP 8X. PCI Express x1 I/O offers 500 MB/s concurrently, over 3.5 times more bandwidth than PCI at 133 MB/s.
Any PCI-E GFX card should do, but as you might not have a sufficient PSU, and as you have a P4, I think the best card at max would be a 8800GT. anything else will be bottlenecked tremendously...
