The Sims 3 Specifications

I now some or most of you probably aren't into this game but I am and EA have released the min specifications for The Sims 3 game which are:

CPU: (XP) 2.0 GHz P4 processor or equivalent; (Vista) 2.4 GHz P4 processor or equivalent [If built-in graphics chipsets then 2.6 GHz Pentium D CPU, or 1.8 GHz Core 2 Duo, or equivalent.]
CPU Speed.2GHz
System RAMXP)1GB RAM,(vista) 1.5GB(if built in graphics add 0.5 additional RAM)
Operating System:Windows XP (Service Pack 2) or Windows Vista (Service Pack 1)
Video Card Minimum: 128 MB Video Card, with support for Pixel Shader 2.0 (NVIDIA GeForce FX 5900 or above / ATI Radeon 9500 or above / Intel GMA 3-series or above
Video Card Features - Minimum attributes of your Video Card Video RAM: Required - 128 MB , )
Video Card 3D Acceleration: Required - Yes
Pixel Shader Ver.: Required - 2.0
Free Disk Space
Minimum: 6.1 GB of hard drive space with at least 1 GB of additional space for custom content and saved games


Now I brought my computer in 2007 and it's specifications are:
I Have: 2 processors running - Intel(R) Core(TM)2 CPU 6300 @ 1.86GHz PASS
CPU Speed 1.86 GHz Performance Rated at 4.89 GHz
System RAM Minimum:I Have: 1022 MB
Operating System: I Have: Microsoft Windows XP Home Edition (Build Service Pack 32600)
Video Card:I Have NVIDIA GeForce 7300 LE (GeForce 7300 LE)
Video Card Features - I have - 512 MB
Video Card 3D Acceleration:I have - Yes
Pixel Shader Ver.I have - 3.0
Free Disk Space : I Have: 130.3 GB

The thing is I'd like the game to play without having to turn the graphics down and without Lag so I'm thinking of upgrading my graphics card to either the 8800gt or the GTX260,Upgrading my RAM to 4GB and also upgrading my PSU as currently it's only 350w so I'll upgrade it to 600w and I'm wondering if you think this will work so I can play it with MAx or at least medium graphics.
I've heard there can be problems with running the GTX260 on a old processor which I'm guessing mine is now.
So any suggestions I'm grateful for.
I only really use my computer for surfing,downloading and occasional game's which aren't as graphically demanding as the sims 3 is so I don't want to spend a fortune.Thanks.

Thanks for the reply.The reason I put CPU SPEED 1.8GHz rated at 4.89 GHz was because when I tried Can You Run It this is what it stated on there.You've made things alot easier for me and thank you so much.