You could always get involved in evolving the existing Amiga emus for ARM handhelds. Especially GP2x/Wiz was neglected when all jumped ship and deving started on the PSP Amiga emu (again). Then came the Pandora, but no portbacks from either it seems
Whatever you build, if it's ARM and going to run Amiga you will need to address this state of affairs. Hell, if it's good and available, I'll buy it.
Apparently it's considered time well spent to dev hardware for a year or two, manuf a couple for proof of concept, and forget about the project. But not to dev software for existing "emu-platforms". Not whining, but noting a phenomenon.
But I'm not discouraging you, and I certainly won't "tell you what to do". So good luck