Hi there,
I have created a fork of this at https://github.com/gnarz/z180emu, where I have implemented a debugger. It is not quite done, but already very usable. I am not making this a pull request, because it is only implemented for linux, I don't program on windows. I just wanted to let you know about it, because you wrote that you intend to add a debugger, and you are welcome to use my stuff for this as you see fit.
-gnarz