Yes I agree it is very doable. We would just have to figure it all out.

As for the heart part, I think it should still be beating. Though we could make it where it beats faster than normal, or slower whichever way we want to go. Because for the change it would make sense that living cell would be needed. Plus like I said the idea of a vampire all of the sudden would be interesting to see. 

I do like the idea very much, it could be fun to play with. Though I agree it might not be the best idea for their bond, fate is always a cause for a strong bond. So it could work, of course there could be more then one reason that they have a strong bond and the hybrid thing could be one of them.

And thank you, it's starting to ease up a bit. :}