If you already have the first HD 7970, yes. The high end cards don't suffer from much micro stutter and scale better than the low/mid range cards. And the AMD drivers now have Frame Pacing which all but eliminates m-s. But be sure you have the PSU necessary for 2 x 250W cards plus the 125W CPU, and good airflow through the case.
Btw, the single HD 7970 is on a par with the 280X, maybe even a bit stronger. But the other cards you list are inferior to the HD 7970.