The poles "as seen from space" would be approximately Orthographic projections. Is it actually as seen from space or is it just a polar aspect azimuthal projection in general? There are others it could be besides Orthographic which would be centred on a pole, but wouldn't be as seen from space. Georeferencing and reprojecting an orthographic projection probably isn't something you are going to find an easy tool for. Converting between Polar Equidistant Azimuthal and Plate Carree though is quite simple as it's just a matter of converting from polar to cartesian coordinates which many graphics tools can do. Stereographic is also a possibility which would probably be as much work as Orthographic, but would give better results in the end since it doesn't "squash" things.

Also, 2:1 is an odd aspect ratio for a world map. There are a number of projections that do project a globe to a 2:1 area, but none of them are well suited to the general reference maps popular on the guild. Plate Carree (Normal Tangent Equidistant Cylindrical/Equirectangular) is good if you want to easily convert to other projections or wrap it on a 3D globe, but it's a poor choice for a finished map for display, Mollweide, Sinusoidal, and Hammer are all equal area and work well for thematic maps but aren't common for reference maps. I think there should also be a parametrization of the Cylindrical Equal Area projection that has an aspect of 2:1, but I don't know the parameters, and wouldn't recommend using any parametrization of Cylindrical Equal Area (Including Gall-Peters and Hobo-Dyer) for anything really as it's horribly ugly.