Ok which mage type fits better?
I was either gonna make a human or an elf...... I think....the human one?
This is a bit lengthy, but I've tried to come up with various things you can use to help in your decision making process.
There are different criteria you can choose from to help you decide, and some of it depends on how you want to roleplay with that in your head vis-a-vis your relationship with Dorian.
The first criteria is obviously between being a Dalish elf and a human noble. Dorian won't have much experience with elves beyond elven slaves, so that adds an interesting dimension, most of which will be left to head canon on your part. In addition, even though you didn't ask about this race, the potential conflict with a Qunari is also very interesting. The human noble, even though he was sent to the Circle, still comes from a place of privilege and is more or less Dorian's peer, which may be important to some players.
The second criteria is the physical aspect of it; what you prefer looking at in the game, and also how you want your Inquisitor to look with Dorian. To illustrate my point, I will say that I won't be able to make a human male mage. I dislike the body shape, and I dislike the way that the Skyhold armor -- the base armor for most of the mage gear -- looks on the male human body (this is mostly covered by my warrior's armor). When I romance Dorian, as I've done for two plays now, I've used a male human SnS warrior.
A third criteria involves the Chantry and the mage/templar decision. A Dalish Inquisitor is a complete outsider to this conflict. That is not to say they have no stake, it affects all of Thedas, but they don't really have a personal history with the groups. The human noble [Codex entry] will have been raised in a religious household until age 10 or so before being taken to the Circle where he interacted with templars and was present for a vote of neutrality in the Ostwick Circle. This may impact how your make your decision during this mission and with other decisions involving these issues.
On the other hand, if you are more concerned with the story aspect and how it plays out in the game, I think both the Dalish and human have strong points. If you enjoy the elven lore, there is significant content in the game relating to that and you may feel that it is worthwhile to play the game as an elf yourself. However, I feel that a human Inquisitor is a more natural fit for the game. Whether that is because the game was originally slated to have only the human race before they got a year extension, some other outside reason, or just my bias showing (which I'm perfectly capable of admitting).
Enjoy your play, whichever choice you make. 