I was looking at HSN last night for the same reason. They have a Singer heavy duty one. Take a look if you haven't already.
http://crafts-sewing.hsn.com/singer-...53&o=&ocm=seis
I emailed Darlene Cahill about the throat measurement and she said is it 6-1/2 wide X 4-1/2 high.
I you find one, please post becsuse I'm looking too.