I am looking for advice on my 2nd rod building project.

Basic Info:
- Fairly new flyfisherman (3 yrs.)
- Only fish for Trout (Michigan & Colorado)
Current Rods:
- 3 wt (Brookies)
- 5 wt Moderate Action (this was my first build ? what a great experience)

Since I have no need for a 7 or 8 wt rod I am thinking about building a 6 wt Fast Action.

My question is if this is a logical next step? Any feedback and/or advice would be appreciated.