So the bodies they'll inhabit are made from their own DNA correct? How much leeway would there be in terms of changing? Is it entirely species based (orc, elf etc.) or is there some room for what they would want? Like if someone wanted to be taller as a very basic example.
I think I could have an interesting character point if there's wiggle room.
Well, the idea was taking the DNA of the deceased fantasy races and then growing new bodies from that, but having them use the soul's memory of their original body from Earth as a basis for the overall structure. So, since the main characters all started off as human, the human-like races would look more like them. It would be kind of like a human actor playing an elf in a fantasy movie. The overall facial structure and body form is similar, but they may appear a bit more slender and have pointed ears instead of rounded ears.
For an example, if Huge Weaving was among our characters and his new body had the blood of an elf, he may end up looking like Elrond.
Or if the actors from D&D: Honor Among Thieves were among our characters, they may end up looking like their characters in the movie.
That being said, since the new bodies are sort of sculpted from their own memories of their past physical bodies, I'm fine with that process being effected by their internal views of how they wish their bodies to be. For instance, if someone was heavily overweight in their old body but viewed themselves as the thin person they used to be, their new body could end up super fit and athletic. Or like in the case you mentioned, if someone wanted to be taller, their new form can reflect that. None of their original body's DNA exists in the new world, however. The new bodies are sort of grown from the DNA of the fantasy races the old wizard collected but the souls' memories of their past bodies are used as a visual guide for how to sculpt the new bodies' physical characteristics.
Hopefully that wasn't too confusing, lol.