Why not do this on the south side? Since you said you need to rebuild that wall anyways, seems like a time/money saver. South side also has the skylights that need replaced. If it's a matter of the way the ground lays, we can fix that.
I have the Harbor Freight ones...when they were new I had no problems moving my 68 Chevelle. Fifteen years later they have gotten a bit harder to use. I have been considering replacing the casters, but I also haven't had to use them in a few years, so they just hang on the wall.