Whirling whips!

[RAGE KING!]

Large whip, and whirlwind attack. One attack against each opponent within 20 feet. Nice. What classes and support feats would you suggest?

[ArmorArmadillo]

Unfortunately for you, here, whips don't work with W-Attack, as they are (technically) ranged weapons. I think it's an awkward way of handling it, but there you go.

[Ulzgoroth]

Unfortunately for you, here, whips don't work with W-Attack, as they are (technically) ranged weapons. I think it's an awkward way of handling it, but there you go.

This is not at all true. I know this has been pointed out before. The only thing that even suggests that is the line:
"Using a whip provokes an attack of opportunity, just as if you had used a ranged weapon."
However:
"The whip is treated as a melee weapon with 15-foot reach, though you don’t threaten the area into which you can make an attack."

I kind of think the weaknesses of the whip would make this useless though, unless you're planning on a tripping or disarming whirlwind. Many enemies are completely immune to whip attacks...