If you are going to use a PC keyboard or do some fixing yourself for the Amiga 1200, try this out:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320135132323>1) What are the principal PC-Adapters and when i can find it?
>2) There work perfectly on Amiga games or so?
>3) After this passage I'll have to convert my A1200 to a >tower?
The Amiga 500/1000 cable connecting to the keyboard can be cut and adapted for the Amiga 1200 and you'll only have to use the green and white wire on the cable (kbclk/kbdata) since the ground is already there on the joystick connector. This should minimize the number of connections you have to solder for the Amiga 1200.
If you run the MPDOS software on a small laptop, it's just as light as using a PC keyboard. The keyboard and mouse will work perfectly on all software since it's a hardware level simulation. I tried it on Marble Madness, Zany Golf, and some others that directly acess the hardware.