The priority sequence from the DK Manifesto is probably the way to go.
But you could make something from a two-step macro, check the Mercurio sticky threads.

With only the default wow UI.
You could use: /changeactionbar 2 and /changeactionbar 1.
And place those commands at the bottom (last line) of each of the two step macros.
Then put them on the same key.
And mash away.

Which would have two macros, both on "1".
Pressing the first changes your action bar to the second.
Which is also on "1".
Pressing that, runs the second and changes the action bar to the first bar.
Where pressing "1" resets the sequence.