I doubt you'll find an OS X dev who will gladly dive into the WinUAE source. It's so extensive that it will take a big effort to even get a decent understanding of it. The only one who seems to be able to even get it to compile on its intended Windows target without asking the help of others is Toni himself!
I run WinUAE through VirtualBox with the Direct 3D addon installed. There are some glitches and stretched graphics here and there and the mouse and keyboard interaction through the virtualization is a bit sluggish, but none of the alternatives I tried were any better.