Two I really like are corn silk and/or cammomile. Corn silk is good for the kidneys and pain or aches from die off. Cammomile (like you said) is good for calming. They are both mild, but what I think you're asking is if some are moldy.
All the brands I've used seem to have been mold-free. Alvita, Seelect (don't know if they're still in business) I've used for years and no mold trouble.
Lately i've used Yogi Tea and Traditional Medicinals. Yogi Tea comes in one called "DeTox." I really like this one. It says it promotes healthy liver and kidney function. Tastes delicious w/ cinnamon and a whole bunch of other tasty herbs. Go easy with this one. I drank 2 cups close together and I could feel my skin hum. Weird. On one cup I feel good though. It has some really beneficial herbs in it.
Traditional Medicials makes Organic Echinacea Plus. This might be good for you as it's for immune support. Also they make organic cammomile and ginger.
Ginger sipped slowly is good for the stomach. As a general rule.
Mint and peppermint are also good tummy tonics.
I would watch out for chai teas as I believe they contain regular caffeine type tea leaves. Someone correct me if I'm wrong, though. :)
You can use stevia to taste per mugful for sweetening. I use 2-4 drops.
I used to buy bulk tea and combine oat straw (silica, good for repairing the myelin, the nerve sheath), corn silk and pau d'arco, throw 3 medium pinches in a large pot of water and bring to almost a boil and shut off to steep. When cool this can be stored for another 1 1/2 days in fridge.
There are so many! You'll have to find your favorites. There are books in the HFS on herbs, so if you want for specific health tonics, go for it. If the HFS does not have a particular bulk herb you think you want, try iherb.com