Going old school there I see.
Have any old Kenwood or Marantz lying around?
For old component speakers like those you would at least a good receiver with the option for input. Then you patch the output of the sound card into the receiver or through a small mixer if impedence problems came up. The output jacks on sound card are 1/8" while inputs on the receiver or amp used would have to be the RCA phone type unless you custom spliced or located the mini to whatever type patch cord used.