Have a look at AMC 20-27, p. 13:
APV BARO-VNAV deviation must be displayed on a vertical deviation display (HSI, EHSI, VDI).
This display must be used as primary flight instruments for the approach. The display must be visible to the pilot and located in the primary field of view (±15 degrees from pilot’s normal line of sight) when looking forward along the flight path.
The deviation display shall have a suitable fullscale deflection based on the required vertical track error.
The nonnumeric display must allow the fight crew to readily distinguish if the vertical deviation exceeds ±75 feet.
If the nonnumeric display does not permit the fight crew to readily distinguish excessive vertical deviations, the approach must be conducted with the flight director and/or the autopilot and a numeric display should allow the pilot to readily distinguish if the vertical deviation exceeds ±75 feet
As long as you can comply with the above, you don't need AP/FD.