"Silver solder" is not a well defined term. To a plumber, silver solder means an alloy containing a very small amount of silver. It is a modern replacement for tin/lead solder, which is no longer used for plumbing because of the health hazard associated with lead. Its melting temperature and mechanical properties are similar to the old plumber's tin/lead solder. It costs about the same as tin/lead solder, maybe a little higher.

Silver solder to a jeweler means an alloy containing almost pure silver. It is very expensive. Melting it requires an oxy acetylene torch. Joints made with this solder are very strong.

I'm not sure what the Sta-Brite silver solder is - I suspect it is about the same as plumber's solder.

Electronic tin/lead solder (60/40 and 63/37) is a different alloy than the old plumber's tin/lead solder. It melts at a lower temperature and is not as strong.

Either tin/lead solder, plumber's silver solder or Sta-Brite should work fine. For soldering steel you will need an appropriate flux. The rosin core flux used for electronic work will not work very well. Get a can of plumber's flux from Lowe's or Home Depot. The flux that comes with Sta-Brite works really well.