Granted, bards don´t have awesome AC at that level. Mind you, if they are not using a two-hander to thwack at the enemy, they have 0 problems strapping a small shield to their left hand and likely outdo barbarians at that level :)
But yes, for healing and tanking combination that is not an oracle or a cleric (so it offers some variety) a druid can do a good job. Personally, I like the base class enough, though a shaman is sometimes a good choice.
BTW, if you are worried about AC, I would advise the Bear Shaman over the Lion one. The speed boost is lower, but the toughness aspect helps. Do note it is a natural armor bonus, so afaik it stacks with enhancement bonuses to natural armor like Barkskin. Granted, your pets don´t look quite so dashing for the picture, but a bear cavalry charge is hilarious in its own right :)