Okay i have to equipt the band with in ear monitoring (2 monitors we dont have room for). I was going to use shure noise reducing phones,get 5 pairs etc but dont know how i would connect these up..which extention cables, if you can buy a headphone multi adapter etc.
im not sure what forum to recommend you to but this doesnt exactly sound like a pit question.

if i were you i would just get like 4 headphone splitters and piggyback them.
use a wireless setup if you are going to use in ear monitors, trust me, you dont want them to be wired to anything other than a belt pack.
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I cant see the point of getting in ears unless you're on a big professional stage.
Good Guitars
Good Pedals
Good Amps

That is all.