Advice on upgrading

[accionoctem]

Alright, I've searched the forums and I'm still somewhat confused as to what I may need to do. I would greatly appriciate it if someone here could offer me some advice.
My current system-
Operating system: Microsoft Windows XP Home Edition
System Manufactorer: HP Pavilion 061
System Model: PC028A-ABA A620N
Processor: AMD Athlon XP 3200+, MMX, 3DNow, ~2.2Ghz
Memory: 448MB RAM
Page File: 553MB Used, 501MB Available
DirectX Version: 9.0c
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1260864&CatId=1882

current video card-
Name: VIA/S3G UniChrome IGP
Approx. Total Memory: 64.0 MB
Integrated

Now, my question, or rather questions. I have the Sims 2 and both expansion packs, however the performance is so poor that I can barely stand to play them. I am not sure just what I need to upgrade though. I assume I need more memory, judging by past threads on here. I also believe I need to purchase a new video card. However with the new video card I fear I won't have enough watt to safely run it. I currently have only 220 watt.

The memory stick I am currently looking at purchasing is the Ultra 512MB PC3200 DDR 400MHz CL3. http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=586829&Tab=0&NoMapp=0

The video card... NVidia GeForce 6600
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1240195&CatId=935

The Power Source... Okia/450 Watt/ATX
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1648064&CatId=1078

Do I really need to buy all of this, and if so will these allow me to run the sims 2 properly?

 

[Lax]

All you'd need to buy is a new Gfx card if you wanna play the Sims 2. If your PSU has enough amperage on the +12v line (PSU 101) you don't NEEd to buy a new one, remember, high watts != good PSU. The amount of RAM you have should be enough to run it (You seem to have 512m already with 64m being used for onboard Gfx?)