you want s-1's and you want to underclock them and undervolt them. they are very cheap used and the fans run very quietly.
I am in the north east . NJ
This is where we need someone to make a case that actually looks like a space heater to house the S1s.
S1s really look like crap with their exposed circuit boards, and you also have to deal with an exposed power supply and PSU wires.
I certainly wouldn't want to use them to heat a normal room in my house unless I could hide them.