One option might be to explore power auras. I know you can set up auras for when rage reaches certain thresholds. I do not know if you can have it set up to check for if an ability is toggled for on-next-attack. In other words I know you can assign something to happen when say rage is above 50, however I don't know if you can also set it up to only show it if heroic strike / cleave isn't already toggled.
If you just want a swing timer you could use Quartz and just enable to Swing timer portion of it. Particularly if you have any other alts that are caster types you may already use Quartz more fully for them.
"In anything, if you want to go from just a beginner to a pro, you need a montage." /w TankSpot WTB Montage for Raiders.