hi they have there own smell and that aint much if anything really BUT thats providing you clean them out at least once a week.
also i think you should read up on ferrets because theres more to it than you think (maybe you have im just saying so you have a little knowledge on them)
and as for noise theres not a peep out them really. you get the odd noise but its nothing bad seriously. they need to be housed,fed,cared for,and lots more things
but as i said books will tell you all that . i think the best book for you would be "james mckay-complete guide to ferrets"
hope this helps. anything