Good info on that site but it doesnt answer my question
which card will you get between those ones R9 290 R9 290X Gtx 780 to run 3 monitors
and adduming that in the future maybe 6month to 1 year I will buy another one to SLI or Xfire ??
A 290X with a good cooling solution looks like the best option to me, but beware, if the cooler is not good performance will not be as good as it should be as you can read in several articles here in tom's hardware.