On my adventure map RP style server I am creating, I finished the adventure world's spawn island, and I've hit a major roadblock. I don't know how to make the main continent of the world. Here is a map I made up in SumoPaint of what my plans are for the world:

and the spawn Island is one of those 3 small ones on the bottom left (for an idea of scale, here is a picture)

So does anyone know what I should use to make the giant continent? Voxelsniper would take too long, and MCEdit doesn't work on my computer (although if it is very good for this kind of thing, I can always do it on another computer)
Any help is appreciated, I don't know what to do
