[Buildroot] gtkmm in buildroot toolchain

[Willy]

Hi, 
I've some program written in c++ and gtkmm. 

Which is the better way to compile them for my embedded system between:

 1. Add (somehow) libgtkmm (and other needed libraries) in buildroot toolchain 
 2. Rewrite entirely my programs with gtk+ (and use always it in future)
 3. Use another graphic library and rewrite all

PS: I need more documentation for buildroot, exist some good book or forum for
rookie users?

Thanks,
Willy