I have been working on the same thing myself.
I got a 5.25" diskdrive to save my disk games.
But never got any real solution for saving cassette games.
However...
once upon a time...
Some of my friends were working on a project involving an amiga soundsampler and audiomaster IV.
and a program to convert audio files to C64 images...
they still do not remember the name of that program.
and sadly my cassette drive is "out of order" so i cannot copy cassette games to C64 disks...
