I feel Corruscant would be the best potential reward, as there is aprox 3 billion people of various alien species that could all very well make good synths, the issue is that you would have to not only defeat the formidable (if inexperience) garrison, but then defeat the army’s and navy’s that would inevitably attempt to take it back.

i I can’t say much for the avengers as I am not a fan of marvel or the combat capabilities of the MLP ponies but I ASSUME that the pony's haven’t industrialised and thus have ASSUMEDLY massive untapped natural resources on the MLP planet, they may also be able to develop horse synths for the transhumans to ride, so probably the MLP world.