I am really thinking hard about giving this system a try. I have a band that incorporates several instruments, ranging from sax to electric xylophone, guitar, bass, Theramin and electric violin. Also drums. How many pieces or units would I need? Five mics. Also, can you use effects pedals with this system?

I'm not sure how many players you have in the band, but we use 5 systems for our 7 piece house band. The drums and bass share a system (with the high bass output option), the two horn players use a system, the last three are guitar/vocals, guitar/vocals and keys/vocals.

Yes you can use effects in a variety of ways.

Sorry I can't be more helpful, but I don't understand how your band is set up well enough yet. Can you give me more info, how many players, how many instruments per player, etc.