Need help upgrading video card and power supply

[chinco16]

Hey, I'm looking to upgrade my video card and power supply. I don't know a ton about making sure everything is compatible.

Here are my computer's specs:

CPU and Memory Processor Brand Intel
Processor Class Pentium Dual Core
Processor Speed 1.8 GHz
Processor Number E2160
Installed Memory 3 GB
Bus Speed 800 MHz
Cache Size 1 MB
Memory Technology DDR II SDRAM
Maximum Memory 4 GB
Number of Installed Processors 1
Maximum Number of Processors 1
System Chipset NVIDIA GeForce 7100 / nForce 630i
Included Drives DVD±RW / DVD-RAM
Hard Drive Capacity 250 GB
Drive Controllers Serial ATA
Video Integration Integrated
Interface Provided Serial, VGA, SPDIF, HDMI, Ethernet 10Base-T/100Base-TX/1000Base-T
Slot Types Provided PCI, Processor, Memory, PCI Express x1, PCI Express x16
Chassis Style Micro tower
__________________________________________________ ___________

Ideally, these are the components I would like to upgrade to:
Video card (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4115418&Sku=B52-9814)
Power supply (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4252527&csid=ITD&body=MAIN#detailspecs)

I guess my questions are:
Are these components compatible with my computer?
Will they fit into my computer's case?
And in general, is there anything I should be concerned with if I try to upgrade with these components?

Any help is greatly appreciated!