Just wanted to say this is my first post on any forum ever, so please go easy on me

So I have a pa4x and my band members recorded each instrument of our song separately as WAV files, so I have about 8 WAV files which are essentially the backing tracks of the song. I was wondering if there was anyway to make these WAV files a style? I already have them separated in percussions, bass, guitar etc.
If not, what's the best way to import these onto the pa4x as backing tracks and play over them? Should I import them as drum kits? Surely there's a better way?
Thanks,
superchunk