Changing A1200 to A600 or C64

Hello, All I am changing an Amiga 1200 (in excellent condition with an M-TEC 1230 8Mb Fastmem axel, a hard drive 10Gb and a bunch of everything) on an Amiga 600HD or Commondore C64 (The condition must be close to ideal both inside and outside) Suggestion to write to jubei@mail.ru