Actually, I can already easily achieve a change of projection with Fractal Terrains. With the software I'm looking for, I need to be able to draw on / paste images directly onto a globe (specifically an orthographic I think that's what the projection's called) representation of my equirectancular map) and then convert the globe back into an equirectangular map, with the edits I made now stretched over the projection. Specifically, I want to be able to paste those maps of the poles onto the world map in globe form, so that the edits will show on the equirectangular map.

And thanks. I've been waiting close to a week for someone to post on this thread. xD