+1 on the Wiha's.IMO over priced for something like torx bits, but they make some great handtools otherwise. Wiha is a great company for bits, very well made and affordable.
I just bought this set of Wiha drivers. It's sizes T3 to T10. The T4 fits my William Henry knife perfectly and it has the smallest Torx screws of all my knives. The right tool for the job.