I don't think it matters what kind of soldier you use because no signal runs through what you're working on. But to be honest, we're all audiophiles here, and you'll buy the silver soldier anyway (As would we all. Just make sure you cryo it first.) lol. The reason they tell you to use an iron, is because you probably don't have much room to work, and a full size gun may not allow you the access you need. Before you buy anything, look everything over really well. You need good lighting, so you might as well set something up now, before you start. Check to see if you can get an iron in below the connection you will be soldering. The tip of the iron will need to be under, and in contact with the metal you are going to apply soldier too. If, for some reason it looks like access will not be optimal, you may be better off getting a gas powered soldering iron or torch. None of this stuff is expensive, it is just a matter of what will fit where you are working. If you go into Lowes or Home Depot, all of these types of soldering tools are right in the same place, next to each other. Just pick the one that you think will work best.
Make sure you put something under what you are soldering to catch any drips. Also, before you soldier the battery, test everything first on a couple pieces of old wire first, just to get a feel for the equipment you bought. Even if you have soldiered things before, not all irons have the same feel, and heating time.
