May I also suggest that if you are uncertain, then you can alway make your own. :)
Spice teas are very easy and ifyou grow your own herbs then you can create your own and know what went into them.
It is no different then making incense or grinding them for spells, potions, or tinctures.
Add ingredients that you like for what benefits you want. Test the different combinations to find a blend that you like.
My personal favorite is spearmint, clove, cinnamon, bay leaf, sage, and stevia (obviously in different strengths). You can use paper tea bags or if you plan on doing this often I would invest in a deffuser so you do not get the paper taste. :)
If you want tea leaves then shop around. You can find that health stores can be s good place to start, or try growing your own if you have the ability and space to.
It is always more rewarding and healthier to drink or eat something you grew or made yourself. :)
Just a thought