"DJing" tips

[Ally]

I may very well be DJing (in the loosest possible sense of the word) for the first time in a club environment, on Sunday night. I know then that the sound system is going to be a step up from the variety of amateur sound systems I've worked with.

First question - I think I'm playing between two band performances so the way is paved for me to be a bit more eclectic with no pressure to lay down a constant four to the floor beat. I'm pretty sure I want to start with what's become a wicked and very personal little recording I have from 1929, trouble is it's very grainy. Does anyone have any good tips or advice regarding cleaning this little bit of music up? Unfortunately the full breadth of the EQ spectrum is used so slewing the EQ doesn't work all that well.

Second question - Am I likely to encounter any frightening flaws in the quality of my music files in the step up in sound system quality? I have music that's sounded fine through some of the systems we've used at parties and the like. As a safeguard I was thinking of planning my set and having full wave files available on my laptop of the music I plan to play.

Thanks,
-Ally