I'm unfortunately not aware of a program that can do what you are in need of either, but it would be an extremely interesting one. I've got no coding experience at all so I don't know how easy it'd be to make, but maybe one of the software developers here would be up for it? An app where you type in percentage of land on the planet, number of continents, number of nations, area of the nations, which nations need to border which, which nation needs coast, and any other fun parameters, and then generates a randomized map from those data, would be quite useful.

Anyone?