|That system is very old... it uses DDR1 RAM... You will need an AGP card, the AMD is a PCI-e, won't work. The Geforce had 2 variants, an AGP and a PCI-e. You will need to get the AGP card, and you will need to make sure that it is low profile to fit in that tower.|
As far as the power supply, there is no way to upgrade it. I know that I've been able to run a GeForce FX5200 in this model before, however I do not know whether it will be able to power the 6200.
As far as RAM goes, this model does support up to 4GB, just use the Crucial memory scanner to get the correct DDR1 type and then you'll find compatible upgrades.
The hard drive should work since this model does have SATA 1 connections, however the speed will be pretty slow because the model uses a very dated SATA standard.
It's not really worth dumping this much money into a machine this old, why are you upgrading it? Why not buy a better used machine online?
You've been helped by a 16 year old.