I've definitely decided to not do the fuel injection add-on at this time.  It's just not worth the disruption to finishing the plane.  I'll revisit it after it's been flying for awhile.

Meanwhile, I also decided to do the fuel flow measurement exactly like the factory does it (as described in the manual).  Basically, cutting in the FT-60 sensor into the fuel line to the right carb.

To do that requires some material and tool purchases...  I asked the factory what silver "solder" they use (it's actually brazing, not soldering) and they said any is fine as long as it's flux-coated.  I don't think that's necessary as long as you use flux (you must with silver soldering), but I did find a top quality flux-coated silver solder to use.

After LOTS of research, here are all the materials and tools I got:

Silver Solder (High silver content makes for a super strong bond).
Torch Nozzle
Torch Gas (Propane is not hot enough for this purpose)
Welding Blanket (you definitely want to protect the engine under the fuel line you're brazing)

Here's info on the silver solder from the manufacturer.  The "Guide" under the Resources tab is useful reading on how to use it.

I'm not coming into this completely as a novice.  I took a "Sculpture and Welding" class way back in college, so I'm fairly comfortable making hot flames. :-)  Maybe after the plane is done I'll start making sculptures again with my new tools. :-D

Another instructional guide on using silver solder (it's oriented toward jewelry, but still useful).