Help on building New Rig

Hello eveybody
I'm in need for your advice regarding my New Rig which i'm right now preparing to buy:
Specifications:
- CPU : Intel Core i7-950
- MotherBoar: Gigabyte GA-X58A-UD3R
- RAM: Patriot Gamer Series 6GB (3 x 2GB) 1600 MHZ FSB
- CPU Cooler: CORSAIR Hydro H70
- HDD: Western Digital Caviar Black WD6402AAEX 640GB 7200 RPM 64MB Cache SATA 6.0Gb/s
- Case: COOLER MASTER HAF 932 Black
- PSU:COOLER MASTER Silent Pro 850W
- GPU: Nvidia GeForce GTX 580
please note my doubts below:
1- I'm planning to overclock to 4 GHZ stable (24/7) as i'm using heaving applications for my work specifically (GNS3 (cisco router emulation software) + VMWare) and they are CPU and RAM intensive so is this i7-950 the right choice along with can i achieve stable overclocking with it to 4 GHZ. (note that i can't afford Core i7-980X)

2- I'm confused about between these two motherboards Gigabyte GA-X58A-UD3R and ASUS Rampage III Extreme and although Asus Rampage III is more expensive but in reveiws they are not much recommended but Gigabyte x58A is recommended in most reviews.

3- This Patriot Gamer Series 6GB i didn't find reviews on them for triple channel memory and i'm worried that these memory would destory my overclocking . i need suggestions from you experts.

4- This PSU is 850W to be ready for SLI but I'm Worried about brand is this Cooler master good in PSU.

5- I not gonna buy this Nvidia GeForce GTX 580 right now simply because it hasn't been released in my country yet but once it is there i will buy it. so based on this is the above mentioned motherboard Gigabyte GA-X58A-UD3R is ideal for this card and for future SLI desgin.

6- Finally the CORSAIR Hydro H70, i heard that it a cool wonderful one but i discoverd just yesterday that Noctua NH-D14 just dominate this H70 and cheaper also but my concern is Noctua NH-D14 is bulky and may not allow me install these RAM (Patriot Gamer Series 6GB (3 x 2GB) 1600 MHZ FSB) as they have tall heat spreaders and may not fit under Noctua NH-D14, HELP PLEASE

PLEASE ANY ONE HAS GENERAL SUGGESTIONS OVER THE COMPONENT PLEASE SHARE YOUR OPINION