I finally placed and paid for my order! After a lot of reading and thinking - a big thank you to everyone on the forum for their support and advice.
I have emailed Lee, hoping to replace LN45145 (EVGA 4GB GeForce GTX 670 NVIDIA Graphics Card - £398 inc VAT) with the cheaper and instock LN45146 (EVGA 4GB GeForce GTX 670 Superclocked NVIDIA Graphics Card - £390.80 inc VAT).
I have also read in previous posts that members of this forum get free delivery? Have e-mailed Lee about that too.
My system is listed below:
3XS Z77 Performance GTX - Custom Series - Updated June 2012
Corsair Carbide Series 500R, Black, Mid Tower Gaming Case
Scan 3XS System - 2 Year Warranty - 1st Year Onsite, 2nd Year RTB (Mainland UK)
1 Asus P8Z77-V Z77, Intel Z77 Chipset - SLI Ready & WIFI!
1 Intel Core i5 3570K, Ivy Bridge, 3.4GHz, Quad Core, 6MB Cache
1 Thermalright Macho Performance CPU Cooler
1 8Gb (2x4Gb) Corsair Vengeance LP, DDR3, 1600Mhz
1 4GB EVGA GTX 670, 915MHz GPU, 1344 Cores, 9208MHz, GDDR5
1 850W Corsair HX Series, Modular, (Dual GTX 680 & ATI 7950)
1 256GB Crucial M4, Marvell SSD, Read 500MB/s, Write 260MB/s
1 2TB Seagate Barracuda, SATA 6Gb/s, 7200rpm, 64MB Cache
1 Pioneer DVR-S19LBK DVD Writer
1 Asus Xonar DGX 5.1 Gaming Sound Card with Headphone Amp!
1 Microsoft Windows 7 Home Premium 64bit - OEM
1 2 Years Scan Extended System Warranty (£1001 - £2000)
1 3XS System Delivery & Setup - Same as above plus all protective packaging removed from within the system, keyboard, mouse and monitor connected and powered on to the desktop.