Opinions on First PC Build

Hey!

So I'm building a PC for the first time and I'd like some opinions/advice. It's intended to be a budget-ish gaming PC (for games like Guild Wars 2, Skyrim, Civ V, browser games). I'll list the parts I'm considering (with links and approximate discounted prices on newegg) getting and I'd appreciate it if you guys could let me know:
1) If these parts are indeed compatible
2) If you would suggest other parts of comparable cost
3) Any other advice, opinions, suggestions

Mobo: ASUS P8Z77-V LK LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel
($105, https://secure.newegg.com/WishList/MySavedWishDetail.as...)
Mobo: ASRock Z77 Extreme4 LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel
($115, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

CPU: Intel Core i5-3570K Ivy Bridge 3.4GHz (3.8GHz Turbo) LGA 1155 77W Quad-Core
($215, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

GPU: XFX Double D HD-687A-ZDFC Radeon HD 6870 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity
($150, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

HD: Western Digital Caviar Blue WD5000AAKX 500GB 7200 RPM 16MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive
($70, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

PSU: CORSAIR Builder Series CX600 V2 600W ATX12V v2.3 80 PLUS Certified Active ($36, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

RAM: G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM 1600 (PC3 12800)
($30, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)
RAM: G.SKILL Ripjaws X Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
($46, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

Case: COOLER MASTER Elite 430 RC-430-KWN1 Black Steel / Plastic Computer Case
($35, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

Monitor: Asus VH238H Black 23" Full HD HDMI LED Backlight LCD Monitor
($170, http://www.newegg.com/Product/Product.aspx?Item=N82E168...)


Thanks!