I know the original post in this topic is a few weeks old, but I wanted to give some input both to the original poster, and anyone considering the same thing.
You could use a low shrink filler, but be prepared to it at lest 2x to account for the shrinkage. It may take more, but 2x is a minimum. It kind of depends on how much of a perfectionist you are.
That is a lot of work, not difficult work, but a pita just the same.
A recommendation I have not seen is using a wallpaper/liner. It is much heavier than your typical print wallpaper. It was made for this purpose. It is not a finished product, you will still have to paint. I wish I could remember who makes this, but if you check with the home decor departments of Home Depot/Lowes they should know what your talking about.