My money would be on Jorah as well. He has given up Longclaw to Jon, but he is still a knight. It seems fitting he gets to wield some sort of Valyrian sword.
Gendry has his hammer, Beric has his flaming sword, Arya has the Catspaw dagger, Jon has Longclaw, Jaime has Widow's Wail, Brienne has Oathkeeper... it really is between Jorah and Sandor out of the Suicide Squad. It might even be that Heartsbane switches hands a few times or the sword itself is melted down to make two new swords. Isn't Heartsbane a greatsword? If they go down the "Gendry-Reworks-Valyrian-Steel" theory some fans have, it could be turned into two smaller one-handed, short swords, perhaps? That way Jorah and Sandor would both get one.