Which would you choose for 126 Rear Hub, Freewheel or Cassette?

After doing some research, Im planning on doing a 7 speed hub + 8 speed Campagnolo Ergo + 8 speed Campagnolo rear derailleur for my 126mm road bike.

Not many Campagnolo 7 speed (126) cassette hubs are available which is leaning me towards the freewheel version as it would be nice to keep all...