I understand your situation and can appreciate you wanting to do the best you can with it. However, you have entered a different world and that world is trailer construction. You need to find someone that has been around trailers for a while so that they can look at your rig and tell you what you are in for. You have taken on a very major project that will need to be undertaken indoors. The appliances are the minimal side of the issues and are not the gorilla in the room. You are taking on a project that would tax a lot of experienced folks. Good luck and keep us posted.