Lets see if I can summarize a $1k build:
CPU - $230 Latest Penryn C2D. Just as easy to OC as the rest of Intels offerings.
Intel Core 2 Duo E8400 Wolfdale 3.0GHz 6MB L2 Cache LGA 775 65W Dual-Core Processor - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115037
Mobo - $86 shipped! Looks like good reviews and OC's well.
GIGABYTE GA-P35-S3G LGA 775 Intel P35 ATX Intel Motherboard - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128084
GPU - $300 - $20 MIR = $280!! Latest and greatest from nVidia!!
XFX PVT88GYDF4 GeForce 8800GTS (G92) 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150261
Case - $91 - $30 MIR = $61 Nice solid construction and affordable, not much wrong with this case. It has room for 2 8800gtx's, so you can fit pretty much anything in this case.
COOLER MASTER RC-690-KKN1-GP Black SECC/ ABS ATX Mid Tower Computer Case - Retail
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=10006342
PSU - $99 - $10 Google checkout = $89 shipped. Solid performer and has 5 yr. warranty. 40A on the 12V rail(s) will handle any single GPU card out there and leave room for upgrades later.
Corsair 520W SLI Certified Modular ATX Power Supply - CMPSU-520HX
http://www.buy.com/prod/corsair-520w-sli-certified-modular-atx-power-supply/q/loc/101/203270716.html
Memory - $74 - $40 MIR = $34 shipped! Cheapest CAS 4 DDR2 800mhz RAM. OC's well and is cheap, what else can you ask for?
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145034
DVD Burner - $34 shipped! Nice "retail" version that comes with Burning and reading software!
LITE-ON Black 20X DVD+R 8X DVD+RW 8X DVD+R DL 20X DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM 2MB Cache SATA DVD Burner - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16827106057
HD - $85 shipped!!
Seagate Barracuda 7200.10 ST3320620AS (Perpendicular Recording Technology) 320GB 7200 RPM 16MB Cache SATA 3.0Gb/s Hard Drive - OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148140
Total ~$1,001 - $90 MIR's - $10 Google checkout = $901!!! $99 under budget! You could upgrade just about any part on the list if you like, but I think this a good solid build that will last for quite some time.
Edit: forgot to mention that the stock HSF for the CPU would be good for mild OC's and if you wanted to OC more than a Arctic Cooling Freezer 7 Pro would be good for most OC'ing needs. If your going to push your CPU harder than I'd recommend the Thermalright Ultra 120, which is about the king right now as far as air cooled HSF's. Here's a review that Anandtech had on the AC Freezer 7 Pro and others:
http://www.anandtech.com/casecoolingpsus/showdoc.aspx?i=3210&p=8
$32 shipped for AC F7P, but usually around $20-$25 at times, so check around before you buy.
ARCTIC COOLING Freezer 7 Pro 92mm CPU Cooler - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16835186134
$66 + Fan of choice $14 = $80 (which IIRC is the Scythe 120mm ones).
Thermalright Ultra-120 CPU Cooling Heatsink - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16835109125
$14 shipped. I'm pretty sure this is the preferred one, but someone who knows more should verify this.
Scythe SY1225SL12H 120mm Case Fan - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16835185059
hopefully this answers most of your questions that you mave have had.