Seed Bank for purple haze?

Hi my brother wants me to grow him some purple haze after next grow as he got his hands on some before and said he loved it and was wondering which seed bank to get this strain from.

the attitude.

Apparently the real purple haze is a clone only and the purple haze in seeds are just crossed with the clone and something else. I can believe this because i've read a lot of purple haze grow journals and they claim the plants didn't turn purple one little bit.