Is a hole in a conductor the same thing as a positive ion?
Neither are true.

A hole has a one unit positive charge. Its position is essentially that of the atom which is short of one electron. When it moves, the atoms do not move, but electrons move to move the vacancy around. The effective mass of the hole is a complicated function of the material. 

A positive ion is an atom that has lost one electron. It also has one unit positive charge, and a mass more or less that of the uncharged atom. When it moves, it moves.

An electron is an electron, with a one unit negative charge.

A negative ion is an atom that has gained one electron, so has a one unit negative charge.