Like Elfwine, I think Edward II would probably be the best match for the Maid of Norway. According to what I read, Eric II of Norway, Margaret's father, asked Edward I to intervene to secure the Maid of Norway's position in Scotland. It seems that, from that moment on, Edward I planned to marry his son Edward II to Margaret: he even had received a papal dispensation ten days after he signed a treaty with Eric II. So, it's likely Edward I would intervene to secure Margaret's position and ensure her marriage to the Prince of Wales.
Of course, if Edward II marries Margaret, then he won't marry Isabelle de France later on. Since the bethroal of Isabelle to Edward II was linked to a treaty between Philippe IV and Edward I, I think it would result in different terms. I'm also starting to wonder who Isabelle de France would marry in such a scenario...
If the Scott truly wish to remain independent (Margaret's marriage with Edward II would result in an Anglo-Scottish Personnal Union), then it's possible they will ask for Margaret to wed John Balliol or Robert Bruce since they are possible counter-claimants. I doubt though that the Scot will wish to risk a war with Edward I.
I doubt Louis X of France would be considered: the French might wish to have the Scots as allies against England, I doubt Philippe IV of France (Louis' father) would see any interests in that marriage. Scotland is too far away from France and, furthermore, too close to England for the Roi de fer*'s tastes in my opinion.
*Iron King. It's a common nickname given to Philippe IV of France because he was described as a very cold being. He is more known as Philippe le Bel (the Fair) in the World though.