You could also use OP25, which imo is the best P25 SDR software available, especially for simulcast. However, for OP25 you should get native linux. As a long time mac-user, I would strongly urge you to find the best native operating system suitable for the software you want to use. Find a used computer for a couple hundred bucks, it doesn't have to be that expensive. You can theoretically run DSD+ or Unitrunker in parallels on OS X, but when it comes to audio decoding you will have major (i.e. HUGE) problems.
You cannot and will not find one operating system that will run all the various SDR/DSD programs that you may want to use. There are some amazing programs that only run on windows (like Unitrunker, DSD+, or SDR Sharp). There are other programs which can only run on Linux (i.e. OP25). Expand your horizons...