Partly, it depends on where you'll be cruising. If your plans include very hot places, I think it's a good idea to mount a couple of small hatches in the "roof" of the dodger, to allow airflow fore to aft for cooling
Also, I like some form of built in water
catchment, so you can refill your tanks
from rain water
(if your water thanks are aluminum, too, you'll want to filter all water you put in them, or get a watermaker
If you run bolt rope
track on the aft end of the dodger, that is a great forward mount for a cockpit
awning, or a bridge to the bimini.
We prefer a shorter dodger than the enclosure in the above photos. Ours is just enough to shelter us, and we have "downwind clears" that roll up to finish the enclosure. We have a half awning for sun shade for part of the cockpit
that zips in, too, so we can have sun protection, but also stand outside it for having a look around. Unlike the poster above, we do like to see our sails
, and want that area clear. Although many friends have enclosures that give them much protection, and we'd consider it if we went somewhere really cold, we do not like the windage they add, as well as wanting to view the sails. imho, the little windows just aren't enough.
Yes to exterior handholds, they can make getting around a lot easier.