there are many types of teas available; they differ from each other due to the type of treatment they undergo after being plucked.
Unless your friend is a connoiseur, I suggest it is more practical to buy him a tea set, those under-a-$100 sets that include teapots to teacups to the chahai, which is the Chinese traditional serving pot. Those even have stuff like stirrer, tea-spoon (literally).
Anyway, good idea to give tealeaves. Fresh, invigorating, original. =)
Douglas