When it comes to OS4 there really aren't many options right now. The A1 is not available at all unless you are willing to pay $1500.00 to $2000.00 US when and if you can even find one. I would say that if you really want to run OS4 the least expensive option would probably be the BPPC and it supports more memory than the CS PPC.
The mac solution just isn't an option, at least not yet. There aren't any confirmed working installations yet that I know of. There are some claims, however even having all of the ingredients I have not been able to even make it boot up past the Kickstart screen yet I have tried. There are several people working with it.
Perhaps the new MorphOS 2.0 and Efika combo for about $400.00 would be a good alternative?
Good Luck,
-Jeff
