Which torch? The classic answer of "it depends".
I use a MAPP torch like torch #3 in your selection list for 90 percent of my silver soldering. It is what I am using for band saw blade brazing in the thread at:
http://www.homemodelenginemachinist.com/index.php?topic=305.msg15401#msg15401
It is suitable for assemblies of brass of up to several ounces in weight.
The main thing I don't like about this type of torch is that it is either on or off as there is no gas flow control knob on it. The only way you can adjust the heat applied is by changing the torch distance from the work.
I don't like the downward pointing torch, #2, as I normally want to heat from underneath the part with a small length of silver solder on top of the joint for most small parts. If the flame is applied to the silver solder, the silver solder will melt before the metal is hot enough to for it to flow.
For very small parts I often use a pencil type propane torch like #2 but with the upward pointing nozzle. This is for parts like .014 wall brass tubing to small fittings. There the MAPP torch provides too much heat too fast, although it can be used.
I also have a torch like shown in #1. I have it connected to a BBQ type propane tank. Mostly it is used for heating my coffee can foundry furnace for small castings, but I also use it as a preheat source for larger silver soldered items such a small copper boilers in the 2 inch diameter x 8 inch long range. There I set the boiler shell up on insulating firebrick and mount the torch to apply a generalized flame to help keep everything hot. Then I use the MAPP torch to move on the boiler to bring the local areas up to temperature for soldering in end caps and bushings.
So as I said. It depends. If I only had one torch for silver soldering, I would chose #3.
Gail in NM, USA