What format to download from Shockwave for narration?

Hi,

I'd like to have music in the background of my narration.  I will download wave, but is it better to download 4 music loops, underscore or the full version?

Thanks so much,

Bari

Full length version (02:25)	US$ 29.95
	Underscore version (02:25) [?]	US$ 29.95
	60-secs version	US$ 19.95
	30-secs version	US$ 14.95
	Set of 4 music loops [?]  1 2 3 4	US$ 19.95
	All versions (wav24 + mp3)