The one I bought at
http://www.industrialpcs.com/p_suppl...7004_12_24.htm
is a 70 watt DC-DC psu for $60 and $4 shipping. It came about 4 days after I ordered it. The best part about this psu for your setup is it comes with two connector cables, one with connections for the motherboard HD, Floppy... The other one has just HD, Floppy connectors.
So it looks real easy to use more than one to get all the power you need.