If I get some free time, I'll have a go with it.

Regarding portability, have you looked at Qt, wxWindows, or any other cross-platform environment? These give you a consistent API so you can port stuff between platforms without changing the source code (obviously you still need to recompile). Most of these are free if you're releasing your program under an open-source license. If you're writing something to sell though, you'll need to pay for them.

Graham.