what would be better gpu ?

Traciatim

Distinguished
Crossfire and SLI generally don't scale well with 3 video cards, and it's a hassle to maintain while AMD drivers need to be updated but AMD seems to ignore everything they possibly can in order to pass the buck as much as possible. Unless you are running 3 monitors or something you probably don't need all that power anyway. Personally I always choose the highest power single video card you can get your hands on, and then if you want more performance later you can pick up a used one if you really don't want to just get the then newest high end performer.