If you go for the i5 you just need to buy a CPU cooler extra, just keep in mind when choosing a motherboard to check the amount of SATA ports. Also do you already have the case, the Cooler Master you mentioned only has room for three 3.5" HDD's.
Thanks, will keep that in mind when choosing a motherboard.
No I don't have the case yet as I am uncertain wether to go full PC or mini-atx. If I was going to go mini-atx then I would have upgraded the 2tb drives to 4tb one at a time over the next few months but if I go full PC, I can keep using the 2tb and just add new 4tb when I need to purchase.