I'd suggest watching this YouTube vid:



I've been interested in living in and using containers for a shop. There are upsides and there are downsides. If you know the downsides I think they are a wonderfully quick way to make shelter. The downsides are they condensate so you'd have to prepare for that for your paintings. They also have been fumigated so you have to either remove or seal the wood floors. It also helps if you have welding and fabricating equipement. The mentioned link is really wonderful if you are interested in living off grid and DYI. there is also a great blog/build on the cabin part here on HMT where a guy made a remote cabin out of containers and it where I learned about the flooring and other egineering problems with containers. Good luck.