Is this a bad idea?

Well since i am moving i have been able to look at all my extra pc's,and i have 5 extra(currently fully working)pc's, though one is already being sold to someone after i move,i also have one that just need a PSU,3 more fully disimabled pc that i need to put back together(they also need PSU's),they range from a 1.2ghz AMD to a core 2 quad q9450.

What i am planing is when i get finished moving and settled in,i am going toset up a HTPC(connected to my HDTV) a audio pc(hooked up to a old stereo receiver and speakers for the 90's lol)and i was thinking of setting up up the rest as file servers,or mabye one of them as a game server.

My main question is,is it a bad idea to set up 4 or more pc's in a closet? I want to put it in there cause i don't want a pile of ulgy ass old pc's sitting in a corner lol.

vetilation is probs your main concern haha

Would leaving the door open a little bit and having a small fan blowing air out be enough? lol

It depends how hard they're working but I would never put even just on computer in an enclosed space. 

Well i am planing on storing all my backed up movies,music,programs,ect,and i may make my dell poweredge server tower run a game server,also i was planing maxing out the fans mounts in any case that goes into closet.

Do you know of a way could set them,not in a closet,and them not be an eye sore?

You could always buy new cases...

1.2 amd is almost usless i wouldnt even use it its a waste of electric. I would resurrect  q9450 and use that but that probbly over kill for what you going to need it for. 

if i could afford to get new cases for them i would just get an extrnal hard drive,but right now,i have no money extra, all my money is going to getting moved 300 miles away from where i am living now..

Well was going to fill it's case with some IDE drives i have lying around(15+ drives ranging from 10gb to 120gb )along with all the others pc's that end up as storage servers,,and right now i am going to need any extra HD space i can get,cause my main rig is almost full,and i can't afford to buy a new drive to get more storage.