Sorry, I can't accept this offer. I do something because I want to do it, money does not matter. (for example I absolutely do not want to learn yet another assembly language or how "other" operating systems handle display, sound etc), also I won't and can't make any guarantees. Never. Sooner or later the complaints start if I have to promise something.
Anyway, IMHO this needs to made in small parts, for example one task would be rewrite of the GUI with something portable (like wxwidgets, MUST use native GUI elements, I hate "alien" GUIs) There is no point in having multiple GUI parts etc..
GUI rewrite is something I can volunteer, someday.. Anything that makes it more portable without taking "lowest common denominator API" path is fine with me.
You realy need someone who knows OSX specific programming (plus preferably C, Amiga and Windows knowledge) I am not interested.