The only other "sophisticated" docker I can think of is the one that comes with XFCE4. (It's nice anyways, for other reasons) I don't know if it has the behavior you specify. There's also pypanel and perlpanel, etc. And Enlightenment has some docks.

You could probably patch gnome-panel or Kicker to auto-raise when a window gives the URGENT hint. It'd probably be a simple patch. But reading the code enough to find the place to patch it would take a while.

I'm almost certain you can do this in FVWM. If you're in the mood for self-inflicted pain. You'd have to basically script your own dock/taskbar from scratch using FVWM's scripting language.