New Gaming PC - about to buy, please advise

Hey there, so on the back of another thread, I learnt it was a better idea to build my own Gaming PC. I have found choosing the components quite difficult as I am still new to this area but I am getting there.

I constructed this build and am looking to purchase very soon:

From Amazon.co.uk:

Monitor -
Acer S240HLBID 24 inch widescreen LED Monitor - Black (Full HD, HDMI/DVI, 1920 x 1080, 100000000:1, 16:9, 5ms) -
http://www.amazon.co.uk/gp/product/B...A3P5ROKL5A1OLE

Blue Ray Reader:
Samsung SH-B123L/BSBP 12x Blu-ray Player (Bare Drive with Software) -

http://www.amazon.co.uk/gp/product/B...rd_i=350613011

From Scan.co.uk

Case:
Coolermaster HAF 912 Plus, Black, Mid Tower Case w/o PSU
http://www.scan.co.uk/products/coole...r-case-w-o-psu = £62.27

CPU: Intel Core i5 2500K Unlocked, S1155, Sndy Bridge, Quad, 3.3GHz, HD3000 IGP 850Mhz, 6MB Cache 95W Retail
http://www.scan.co.uk/products/intel...che-95w-retail

Power Supply:
650W PSU, Corsair Enthusiast Series 650TXV2UK, 85% Eff', 80 PLUS Bronze, SLI/CrossFire, EPS 12V, Quiet Fan, ATX v2.31
http://www.scan.co.uk/products/650w-...2v-quiet-fan-a

Graphics Card:
MSI HD 6950 Twin Frozr III Power Edition/OC AMD Radeon Graphics Card - 2GB

http://www.scan.co.uk/products/2gb-msi-hd-6950-twin-fro...

RAM:
4GB (2x2GB) Corsair DDR3 Vengeance Jet Black, PC3-12800 (1600), Non-ECC, CAS 9-9-9-24, XMP, 1.50V
http://www.scan.co.uk/products/4gb-(...-9-24-xmp-150v

Hard Drive:
1TB Western Digital WD1002FAEX Caviar Black, SATA 6Gb/s, 7200rpm, 64MB Cache, 8ms
http://www.scan.co.uk/products/1tb-w...64mb-cache-8ms

Motherboard:
http://www.scan.co.uk/products/asus-p8z68-v-intel-z68-s...(x16)-vga-on-board-atx
Asus P8Z68-V Intel Z68 S1155 Motherboard

Keyboard:
http://www.scan.co.uk/products/keyso...-and-flat-keys
Keysonic KSK-8004U Full size keyboard with modern design and flat keys

Cooler:
http://www.amazon.co.uk/Cooler-Master-Hyper-212-Plus/dp...

1) First of all, are these products compatible with each other?
2) Are there any better alternatives for the products I have chosen? Or cheaper for a similar value product? I would love to cut costs wherever possible

I am not planning on having two graphics cards or overclocking.
If you have any recommendation/advice that would be really useful!

Thank you very much! I would really appreciate any help as I am looking to buy this ASAP.