Alright... what I did was totally MAD, but it worked:
I opened Parallels and booted into Windoze... from there i installed Bochs and used the guide... and it worked: Rhapsody working in colors at 800x600... but it was hwll slow...
I still cannot figure out how to make bochs work in OSX... now it tells me that the graphic library (I tried several... carbon, X11, SDL...) isn't installed.
I don't know what to do, please help.
P.S.: if you want I can post the picture with Mac OS X with Parallels and Windows which has inside Bochs with Rhapsody in the Laugh section

Mac OS X --> Parallels (Windows) --> Bochs (Rhapsody)
EDIT:
Now Bochs in Mac OSX works through DarwinPorts... and it's even slower than Bochs in Windows inside Parallels.
EDIT 2:
After playing around a bit with Bochs options I manage to have a decent experience with Rhapsody.
I used Bochs in Windows inside Parallels, because OSX Bochs is too slow.
The problem, obiously, is that if I want to use Rhapsody, I have to boot Mac OSX, open Parallels, boot Windows, then, inside Windows, open Bochs and boot Rhapsody...

Too complex, too slow overall... however, I'll try resurrecting my old Pentium 233 MMX with my Matrox Millennium MGA, which is supported by Rhapsody.
Thanks everyone for your efforts!