The Cape Dory 30 was actually offered with 3 different steering options. The one in the picture above is the Edson Pedestal option. If you want to see the compass or electronics with this setup, you really need to stand but you can steer sitting down otherwise. There was also a schooner style which utilizes a worm gear drive. This option is less responsive but very rugged and doesn't take up much cockpit space. They also offered a tiller option but not many were rigged that way.
It is certainly possible to convert from wheel to tiller on these boats. The top of the rudder post is easily accessible and all of the hardware exists to make the swap without custom fabrication.
If you are really interested in a Cape Dory, I would suggest looking at capedory.org as well since it is dedicated to these boats.