RE: correct type of solder?
For the amount of silver-soldering most modelers will do... just get the "syringe" of paste silver solder from Radio Shack. One syringe will do the 4 joints in cabanes for a .60 size biplane with some left over.
You definitely want a silver-bearing solder for landing gear or other structural joints on the model. Its MUCH stronger than tin-lead solders.
If you are going to be doing a couple of models a month that need the silver-solder joints... I know someone to ask about the source for the stuff at a bulk rate. (1 lb minimum... and that would be fairly expensive...)