From your description, the project is far to complex to be addressed through a bulletin board posting. This type of design requires the services of a professional engineer (civil or structural) and/or an architect.
The sizing of floor and ceiling joists requires information regarding the spans, bearing wall locations, loadings, etc. Even the rafters probably need to strengthed to support a new ceiling.
When adding a second story, the foundation typically must be strengthened to take the increased load and the lateral load resisting system for the overall structure (e.g., shear walls, tie-downs, bracing, etc.) must be upgraded.
Check with your local building department for permit requirements - in my area, you must have plans signed by an engineer or architect for major additions or remodels.