Build help please :3

first off HI :D im new to tek syndacte forums and figured this would be the best place to get reccomendation and pointed in the right direction

so im finally in a position where I can spend a reasonalbe amount of money on a high end gaming rig and wondered what would you guys recommend, I have not kept up with the market as much as should have but did not expect to be in a position to get more or less what ever I want that being said I want the best cost to performance ratio possible. I am not 100% sure with what I should go with right now there are just so many possiblites and bottle necks that I am probably not aware of, I would appreciate it greatly if anyone could help me make a part list for the optimal ultimate gaming rig, I have some parts from an old build that are still usable and a general idea of what I would like to get and would like to know what you would change :) this  will be used many for 1080p gaming on a single monitor right now BUT I do want to upgrade my display situation asap to higher resolution setup be that a single monitor like a cat leap or a 3x1080p setup, I do have a fair amount of building experience but not within the last few years due to a busy schedule and lack of funds to even bother but now that completely changed and its time to get back on the horse! 

I would also like to say thank you in advance for anyone who has the time to help me out :D

                                                                                                what I do have:

  1. 2x 1.5tb seagate barracuda HDDs
  2. 1x samsung 830 128gb SSD
  3. ultra x3 650watt PSU(not sure if this will be adaquet or not got it on sale a couple years ago before I knew I could do better)
  4. windows 7 ultimate 64bit

                                                                                                   what I was considering

  1. fractal design define r4 chasis
  2. asus sabertooth z77 LGA 1155 mobo
  3. not sure what kind of ram to go with there are SO MANY OPTIONS
  4. gtx 680 (only because I dont know much about ati cards ive never had one but would not be opposed to buying one)
  5. probably a seasonic psu 
  6. as far as cooling goes I will be putting in a custom loop then over clock the pants off of it