Upgrading and scavenging parts for a new system

[atomiktoaster]

My fiance's laptop is almost 5 years old and was of questionable quality to begin with, so I'm looking to build a replacement, while at the same time upgrading some of the weaker parts on my gaming rig. Her machine will be for internet surfing, Office and basic tasks like that, no FPS gaming, video editing or torrenting. She wants a smallish case, so I'm looking at a microATX build. I have a student copy of vista 32 and 64, and I'm not sure what would be best in this case. My machine is set up to triple-boot XP32, Ubuntu 8.10 and Win 7 32 right now, but I mostly use XP.

The parts in my machine that I'm thinking about upgrading and reusing:

CPU:
Pentium D 925 (looking at replacing it with a e5200. How much performance increase would I see with a stable overclock on air, with either a stock cooler or a darkknight?)

GPU:
8500 GT (I bought an 8800GT a while back, so this is sitting in the closet ready)

RAM:
2X1 GB Crucial Ballistix DDR2-800 (not as sure about whether I should upgrade this in my machine or just buy new for hers.)

Here are the new parts I have in mind:
PSU:
CORSAIR CMPSU-400CX 400W bought already for $30 after MIR

Case:
HEC 6T Series 6T10BB Black 0.7mm SECC Steel MicroATX Mini Tower $40 with free shipping

Motherboard:
ECS GF7100PVT-M3 LGA 775 NVIDIA GeForce 7100 HDMI Micro ATX $50 after MIR

RAM:
Need some help deciding on whether to buy 2 GB for her, 4 for me and giving her the 2 I'm using, 4 for her and sticking with 2, or 4 for her and buying another 2 to get me to 4. I'm not sure I'd notice moving to 4 GB in XP, and I'm not sure if she'd need 4 GB for basic apps in vista.

HDD:
Western Digital Caviar SE16 WD6400AAKS 640GB 7200 RPM $60. She's doing ok with 80 GB on her laptop, but there's not much money to save in going to a smaller drive. I do not want to mess with cloning my 400 GB HDD to the bigger drive and giving her the smaller one.

Optical:
Whatever the cheapest retail sata burner is when I order this stuff.

Monitor:
Acer X203Wbd Black 20" 5ms Widescreen LCD $130. This is just a guess, because she thinks my 22" Acer at home is too big, and kind of want a second 22" like I have at work. We need to go to bestbuy or fry's and look at some in person to pick a size and resolution, I think.

The current list is adding up to around $400. I'm ok with waiting for newegg deals to roll around again and buying pieces in separate orders, but there's only so many parts I can really watch. Are there different parts I should be tracking? What should I do with the RAM? This will be my third build, but it's always good to get other opinions, even this isn't a i7 build with tri-SLI 280 GTXs.

 

[Proximon]

MB: You'll have better stability, reliability, and functionality out of an Intel chipset:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128388

RAM: She'll be fine with 2GB. I have no idea what you need as you didn't mention your usage, but it's cheap right now. Always get low voltage RAM, and 800Mhz is just fine with Intel builds.

 

[atomiktoaster]

Any reason to go with the G41 vs the G31, considering that I'll be using the 8500 GT for graphics?
GIGABYTE GA-G31M-ES2L LGA 775 Intel G31 Micro ATX Intel Motherboard

That said, I've had a pretty decent experience with the XFX 680i LT I'm using now on my machine.

At this point, the most demanding thing I'm doing is gaming at 1680 x 1050. Left 4 Dead, TF2, and Bioshock recently. The next thing on the horizon is probably Diablo 3.

 

[macabre215]

Ram is really cheap right now and with 64-bit OS running smoothly with 4GB of ram I wouldn't skimp here for either one of you.

GeiL 4gb kit http://www.newegg.com/Product/Product.aspx?Item=N82E16820144073
has good overclocking potential with the E5200, and try getting an Intel chipset with a good aftermarket HSF. Overclocking the e5200 to 3.4-3.6 can be fairly easy with a decent board.

I've heard nothing but good things about the GIGABYTE GA-G31M-ES2L for overclocking, and it's very cheap. I have the same monitor as you are looking at and love it, everything else looks good to me.

 

[atomiktoaster]

I'm planning on putting the old Pentium D 925 in the new mATX board and using the overclocked e5200 in the XFX 680i LT that I'm currently using in my gaming rig. I know a P35 or P45 would be more stable, and would probably be better at overclocking the e5200, but I don't want to replace my motherboard at this point since she wants to keep the computer in a pretty small space under her desk (hence a mATX case).

 

[shortstuff_mt]

A Pentium D, mATX board, and small case sound more like a space heater than a computer. Are you sure you can't just ditch that crappy Pentium D and pick up an E5200 for each computer? The E5200 is a great chip! I recently built a computer for my parents using the E5200 and easily overclocked the chip to 3.4GHz using only 1.2v and a stock cooler from an E6420.

 

[atomiktoaster]

The space heater aspect had come to mind, though at stock speeds the core temp for the D usually stays below 50C with the generic heatsink I have on it IIRC. The 8500 GT isn't a huge source of wattage, but it does have a passive heatsink, which would like some case airflow. I'd like to find a smallish case with a pair of 120 mm fans, intake and exhaust. I'm not sold on the compucase, but antec's smaller offerings are at least twice as much. Suggestions?