[Windborne]

Hidden bases don't need to be in a nebula, armor four or five gives you camoflage armor that lets you cloak your ships before cloaking devices come Online and provides some defense too. Build space stations in astroid belts with remote miners on them, and cloak the ship, later scrap these and build base-ships so you don't have to worry about the astroid/planet your looting becoming strip mined and useless.