OS4.1 is not available for A1200's with or without a PPC accelerator. You need to get a Sam/Pegasos 2/AmigaOne motherboard to run that.
OS4.0 is available for a 1200 with PPC (you really do need a gfx card for this) but i would suggest paying for a new Sam motherboard, or second hand peg2, and getting OS4.1 as it is much better, and not too different in the price paid.
