Funnily enough, I was looking for chamomile plants recently too, and couldn't get one for love nor money. I've not been able to get any French Tarragon either.
And I never know whether that rogue 'h' should be there either. But I like to put it in, even though my standby box of teabags doesn't have the 'h'. The RHS book of herbs says 'chamomile', I'll go with whatever they say!