If you want to keep it simple, what about MS Paint?
Seriously, the easiest and safest solution to this is the GIMP. (avoiding dependency hell)
Just create each item of furniture on a seperate layer (as simple as going to "layers" and clicking "new layer", then that way, each item is on a seperate sheet of acetate if you will, and they can all be moved independently.
This also has the advantage that I've never had the GIMP fail to install yet, even on Slack 9.1 it went like a dream, and you also have an extensive availibility of information on the web.