I seem to remember that the A500 PSU was better for expanded 1200's but I cant remember if it was the heavy type or the light type of PSU. Needs to power the spec below. I have a converted AT PSU at the moment but its messy.
If you have such an item for sale, please get in touch.
Amiga A1200 Desktop, Apollo 040/33MHz, 32MB RAM, IndiVision, Slim DVD-RW, IDE-Express 97, 4GB CF/IDE Adaptor, 10MB PCMCIA Nic.