Well the specs am giving will be a overkill but it will last you easy for 3 to 4 yrs without any upgrades...
Intel Core 2 Quad Q9550 Yorkfield 2.83GHz 12MB L2 Cache LGA 775 95W Quad-Core Processor - Retail $279.99
Free Shipping*
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115041
GIGABYTE GA-EP45-UD3P LGA 775 Intel P45 ATX Intel Motherboard - Retail $134.99
($114.99 after $20.00 Mail-In
Rebate
2 oz copper PCB + Easy Tune 6 for OC
2x Winner of Customer Choice Award - Intel Motherboards
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128358
G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail $44.99
Free Shipping
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231122
Western Digital Caviar Black WD6401AALS 640GB 7200 RPM 32MB Cache SATA 3.0Gb/s Hard Drive - OEM $79.99
Free Shipping*
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136319
1. Antec EA650 650W ATX12V Ver.2.2 / EPS12V version 2.91 SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail
2. Antec Three Hundred Black Steel ATX Mid Tower Computer Case - Retail
Total - Combo Price: $119.94
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.158005
SAPPHIRE 100259L Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail $189.00
($174.00 after $15.00 Mail-In
Rebate
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102810
Totals around $850 without rebates...So well within ur $1K limit...and a very powerful rig...