Techmanager6000 has always been sold on cd, and the cable is proprietry, so Keysoft is the only source unless you find a second hand set on ebay or somewhere. Bear in mind the software does not work in XP.

Recording is just a question of connecting line out to line in on your soundcard and having some software. If you have newish Nero or Roxio cd/dvd burning packages reasonably serviceable free wave editors are bundled which can be used for recording. Otherwise look at the free Audacity: http://audacity.sourceforge.net/about.php
to record your cd quality wave files. The last time I used CDex, which was a long time ago now, it was free and is a good MP3 converter/ripper for an alternative: http://www.cdex.n3.net/