Thanks everyone such your input and getting back to me so quickly!
I just assumed that as the motherboard has a max RAM capacity of 16mb, I may as well fill up the slots and if one RAM goes back I can just replace that one. Would 2x8gb RAM be quicker than 4 x 4gb RAM?
Yes I wasn't sure about the PSU wattage and make (CoolerMaster 650W). Would 500W give me enough for upgrades in the future? I have never had more than 450w in the past. But All my systems in the past have been rather modest and standard cheaper ATX PSU where used. I am certainly convinced to avoid cheap PSU's.
As for the processor. I thought the 8 core would pack some punch over the intel quads? I use some analysis software which allows you to select the number of cores you have to speed up the analysis. I thought 8 cores may help me with that.
2x8gb RAM won´t be quicker than 4 x 4gb, but it would be cooler, tough a lot more expensive. In terms of ram get a 1333MHz kit with as low latencies as possible. 16GB Ram will be soon the average amount of ram in most computers.
500W won´t give you enough room for any upgrades in the future -- assuming you are referring to video card. For a SLI 2x config you need a 750W PSU.