Chipset

[Blue Flux Blazer]

Thanks for helping me build my first computer last fall. I'm working on a second one, and I hope I'm not too far off track. If you want to skip the following paragraphs, my question is whether the chipset balances with the system listed below.

In January, I built a little machine (Asus M4A78LT-M LE motherboard, Sempron 140 CPU 2.7 GHz, 1GB memory, LG DVD burner, a friend's IDE HDD out of a computer that was headed for the trash, and Linux Mint 8 LXDE) so my wife could check her email and do her “farming”. Other than basic computer uses, we also like recording OTA broadcasts with Windows Media Center on a Vista machine I'm selling. The computer I built in January was made with the idea to have the option to add Windows 7 and cards from the Vista machine and move it into the living room, if needed. Well, the time has come sooner than I thought, and I have been working on what I wanted to add to fit our changing living room needs.
Our family only does basic gaming, including Webkinz.com. Well, that all changed recently. Our four kids, (9 to 3 years old) gathered around and watched my wife and I play Google's doodle two player Pac-man. My wife enjoyed watching each child delight in taking turns being paired with me, playing together. We decided we wanted to expand the capabilities of the living room computer, so later when I was putting together an order, my wife said to me, “Make it so it can also be a gaming computer later.”
I know I'm going about this backwards, and I should have bought everything all together at the same time and posted a question before buying parts, but hopefully I've got a pretty balanced system that I can add to in the future. Below is the system of what I actually own, just ordered, and also plan on adding:

Asus M4A78LT-M LE motherboard

AMD Athlon II X3 440 Rana 3.0 GHz

Corsair XMS3 4GB (2x 2GB) DDR3 1333 TW3X4G1333C9

Antec NEO ECO 620C 620W PSU

WD 1TB Green HDD

LG DVD/CD burner with Lightscribe support

Linksys wireless 54g PCI card

Asus PCI-E tuner card

Asus USB tuner

Windows 7 64-bit

I'm now planning on adding a video card later (hopefully I've left enough PSU wattage of headroom) and I'm guessing I'll need a WD Black HDD later. I see a lot of recommendations for WD Black for gaming systems, but I'm not sure how that would work in this system (do you save the games from the optical disc to the HDD and then play the game off of the HDD? Or just play off of the disc in the ODD? Or is it that the OS just needs a faster drive?)


From reading the sticky about gaming builds, my main concern is about the chipsets (if I should be concerned about anything else, please let me know). I don't know much about chipsets, so I'd like to know if they are appropriately balanced to be with the rest of the components. My fear of commitment has me wondering if I need to buy a different motherboard before I put the OS and motherboard together forever. I could keep my existing motherboard with the original system, so I'm fine with buying another Asus motherboard, if I need to. I made sure the memory was on the QVL for the existing motherboard, so hopefully the Corsair memory would work if I need to get a different motherboard.

Thanks in advance for answers,

Cory

[glc]

The ONLY thing you need to make that a decent gaming machine is a video card. Your power supply is strong enough to power any single card on the market at this time.

[Blue Flux Blazer]

OK! Thanks, GLC!

What would be a "sweet spot" range of card that would fit in nicely with this system? And maybe also same question for a notch below the sweet spot?