ORIGINAL: abufletcher
I just use any old cheap (copper) wire from the dollar store. The thing to remember is that the wire isn't for strength, but just to bind the parts together while you're applying the solder (and maybe to give the silver solder something to flow around for a thicker joint). I've also had luck joining thick music wires with a section of brass tubing. For heat, I just used a 100w iron (about $15) but I make sure to give it at least 15 minutes to warm up. Then I add a couple drops of the liquid flux, heat it until it starts to ''boil away'' and then touch on the silver solder, which should flow right away into the joint.
I agree the trick is to let the soldering iron come up to full tempature before proceding, something I think a lot of newbies fail to do. I also like to heat the parts a bit before adding the flux and then apply the solder when the flux starts to boil.