I have my desktop (specs below) and a server rack by my bed (on either end), my room sounds like a jetway, so I think you can deal with a few random HD clicks, so your probably fine with 4. You can get OEM 1TB drives for 99, so get 2 of them
. Heat wont really be an issue, but may I suggest fans?
For the record I have never gone RAID, when I was idk like 10 my mom had a machine built for me what was RAID, anyway, one of the drives crashed and I lost like 4 years of my life.
So now I have about a dozen of 1TB drives floating around the house and city with backups of my working files, haha.
Speaking of raids, I should probably go raid5+1 to where all my drives are striped, safe if one fails, and can be added onto. I think thats the one I want, haha.