I've been drinking powdered tea, I get the large "4C brand" canisters of Lemon Tea with sugar sweetener (not so good to drink constantly, if you're pre-diabetic), or the Arizona Green Tea, or Arizona Arnold Palmer half&half Tea/Lemonade powder. (4C also makes a good Half&Half Tea/Lemonade powder.)
Another one, is a Lipton Black Tea (Unsweetened). That's good, if you want to cut down the sugar.
I get all of these in multi-packs at Walmart.com, for a reasonable price.
Also, my local Shaws has an aisle section with powdered drinks, that carries the 4C Lemon Tea powdered tea mix as well, if you don't want to shop online.