Yeah, that's why i was looking for a 19" rackmounted case that can fit in (like this one [sorry french link] http://www.ldlc.com/fiche/PB00160735.html got 6 x 3"1/2, good airflow and 2 additionals 3" 1/2 slots but it takes 4U [that is not a problem, my rack is nearly empty])
For now, i just find it with poor features like old Xeon and 8GB RAM ...
For information, i don't care about the rack, just that i was thinking put it in, to hide the nerd stuff i got, my gf doesn't like the mess i have and it'll be worse with time.