Which software to get?? Audirvana, Decibel, Pure?

I have a Mac Mini that I use for playing my cd's- most of which i ripped into iTunes in either WAV or Apple Lossless. I like internet radio listening too. We watch Netflix on it and I surf to look stuff up, pay bills etc.
Rest of system: Benchmark DAC1, Plinius 8200 MkII power amp, Tandberg 3006 amp, Platinum Audio Solo 2-way stand-mounted speakers, Tara Labs RSC Master Gen II IC (unbalanced), Kimber KCAG IC, Tara Labs RSC Prime bi-wire speaker cables, DH Labs digital coax, Lifatec Silflex toslink cable.
NOW....which software would most improve my system? I tried BitPerfect---i really am not sure i hear any improvement and some of my music will not play with it engaged.
Any advice gladly accepted...about software OR hardware.
Thanks!!!