I needed a new cordless for work so I looked into buying one that could power an 8" auger as well, mine is also a Mora. Opinions vary on which drill is best, but I settled on the Milwaukee fuel 1/2 hammer drill/driver with the m18 red lithium xc 4.0 batteries. For an adapter I went with the Ice Master. There are some real good video reviews on youtube that may help you to decide what set up is best for you.
It's still a bit early in the season for me to give a full and fair review of my set up, but so far I love it. I have probably drilled 50-60 holes in ~ 6" or so of ice so far. I drilled about 40 holes one day and did not have to change the battery. How many holes I get in thicker ice remains to be seen.
By using the Ice Master adapter I am able to quickly remove the drill and use it for work. From what I gather the Clam plate requires you to remove the chuck thus making harder to use the for other purposes. The other benefit of the ice master is its small size. Never having used any other set up I can't really say whats best, just reporting what I have found from my own first hand experience.