Singerco.com has free manuals you can download. I highly recommend you do. I like Touch & Sews. They're descended from the 400 and 500 series slant needle machines. The only downsides are the plastic gears that were already mentioned and the fact that they're not an intuitive machine. You need the manual to get the most from them.
They use the 2 pc. plastic bobbin with white stripes. I bought some at a Hancock's Fabrics store. You can also get them online. Make sure the bobbins are screwed together correctly. Any looseness and your machine will jam. I learned that one the hard way.
You want the black Singer tophat cams. The white ones are for the 700 series and won't work correctly. The tophat cams are easily available.
I hope this helps,
Rodney