making music tracks
what is the best software to remove vocals from music to make Instrumentals or karaoke tracks?

I just want to know what to buy in order to make some instrumentals and cover a few songs.
I am an aspiring gospel rapper. I have been working with magix music maker to make my own Beats, but I am considering putting out a Gospel mixtape, so i want to use some beats that folks are familiar with, minus the original vocals. I really appreciate any help or advice you guys can give.

sony acid 6.0
you can also get their free express pack