Anyone?

Hello, I'm fairly new mining, I've been mining for about a week with my laptop that does 24Mh/s, and it feels that it's going no where so I found this two gaming rigs on Craigslist that looks very promising for mining, I hope someone with moreknowledge on hardware can give me better advice, I feel like the first one can do better for mining but I could be wrong. Thanks ahead of time.
1-
Custom Gaming Computer - $940 OBO

CPU: AMD Phenom II 955 x4 @ 4GHz stock voltage tested stable in prime95 water cooled
GPU: XFX 7950 Double Dissipation with lifetime warranty
DRAM: Two 8GB Crucial Ballistix Elite Rated for 1866 at 9-9-9-27 1.5v currently tested stable in prime95 at 1600 7-7-7-21
Storage: Sandisk 64GB SSD 490MB/s read
Main board: MSI GD-65 890FX with two full 16x PCI Express 2.0 Slots
PSU: XFX Pro 550w 80 plus efficiency
Case: Black Antec Lanboy Air
Disk: Lite-On DVD burner 24x read

2-800
CPU: Intel Core i5-2500 3.3GHz Quad-Core Processor
CPU Cooler: Cooler Master Hyper 212 Plus 76.8 CFM Sleeve Bearing CPU Cooler
Motherboard: MSI H67A-G43 (B3) ATX  LGA1155 Motherboard
Memory: Kingston 8GB (2 x 4GB) DDR3-1600 Memory  
Storage: Seagate Momentus XT 500GB 2.5" 7200RPM Internal Hard Drive  
Storage: Western Digital Caviar Black 1TB 3.5" 7200RPM Internal Hard Drive
Video Card: Sapphire Radeon HD 6850 1GB Video Card (2-Way CrossFire)
Video Card: Sapphire Radeon HD 6850 1GB Video Card (2-Way CrossFire)
Sound Card: Creative Labs Recon3D PCIe 24-bit 96 KHz Sound Card
Case: Rosewill RANGER ATX Mid Tower Case
Case Fan: Cooler Master SickleFlow 69.7 CFM 120mm  Fan
Case Fan: Cooler Master SickleFlow 69.7 CFM 120mm  Fan
Power Supply: OCZ ModXStream Pro 500W 80 PLUS Certified ATX12V / EPS12V Power Supply
Optical Drive: LG BH14NS40 Blu-Ray/DVD/CD Writer  
Operating System: Microsoft Windows 7 Home Premium Full (32/64-bit)  
Keyboard: Cooler Master CM Storm Trigger Wired Gaming Keyboard