from the bath fan to the outside?

We are converting a bedroom into a master bath ... size is 10x11. The room is at the north corner of the house on the ground floor. We live in NW Arkansas. The house is a 60's ranch with a full basement. 8' interior walls, 2x4 construction, brick veneer, hip roof, 18" soffits ... we have soffit vents and a ridge cap vent to vent the attic.

We are putting in a 150 CFM bath fan on a timer switch. I'd like to duct it to the soffit about 6' away. That OK? If so: 1) should we use insulated flexible duct?, 2) do we need a backdraft damper?, 3) any suggestions on what kind or brand of termination hood to use at the soffit?.

Thanks in advance.