You can use pine, but it it usually avoid since poplar, basswood, ash, and alder are superior hardwoods and not nearly as soft and cost right about the same as pine. Oak has been used, but is generally not used since it is very heavy, and not as dense as some other woods for the weight. But it can be used. Usually you are not going to find thick enough wood at your normal hardware stores. They are usually only 1" thick, and I rarely find hardwood their that is dried properly, and to the right amount. You are better finding a local lumber mill and buying from them.