even from a commercial view is 68k the best option right now (most users and developers, most software including compilers, most documentation, running almost everywhere including Android). That "might" change with a native Raspberry AROS version but that is not reality right now. AROS 68k is even used in Icaros and Aeros for 68k emulation so 68k offers the biggest base. Only if you want to use specific features of f.e. AmigaOS (4.X) or MorphOS you have to use real crossplatform compilers for development.