I will give a mini review of a few Gransfors axes that I have.
First an image to show relative sizes.

I have the Splitting Maul, Scandanavian Forest Ax, the Hunter's Ax, Swedish Carving Ax, and the Mini. All but the Mini are described at the GB site.
http://www.gransfors.com/htm_eng/index.htmlAs stated above the intended purposes choose the ax.
The 5 GB axes I have are all for different purposes and reasons, but the 3 that are most appropriate to this forum, in my view, would be the Scandanavian Forest Ax, the Hunter's Ax, and the Mini.
Scandanavian Forest Ax is a 3/4 size Hudson bay type ax and best suited for truck or canoe carry where serious firewood needs would be the prime purpose. The larger felling ax would be even a better choice if major wood operations was the goal. I carry my SFA in the truck.
Hunter's Ax or Small Forest Ax are super tools for firemaking . These are the same overall size but the forest ax has a hammer poll and a slightly different shaped helve. The Hunter's Ax is my favorite GB but I would probably buy the small forest now for the hammer poll. I use this one for small fires for cooking, boiling etc.

My most recent addition is the Mini. This is a very small---coat pocket sized ax. It is very light and handy again for the lunch time boilups. I have not extensively used this ax yet but I am prediciting it will become a commonly carried tool.
So my choice for your stated purpose would most likely be the Small Forest Ax or Mini.
I recommend Daren Cutsforth as a source. Service is excellent. I also caution that GB will be raising prices significantly due to the dollar strength soon.
He currently has the Hunter's Ax on sale for $69, and good prices on the rest of the line.
http://www.cutsforthknives.com/