Building Speaker Cables

Don't know your definition of "overkill" but soldering is not necessary with those connectors and that wire, and you will never reliably discern any sonic difference/improvement from doing so.  Coat the wire and connectors with ProGold, use the set screws to secure the wire to the connectors, add your heat shrink, and enjoy your new cables.  BTW, if you ever decide to upgrade or change your speaker cables, you may be thankful for how easy it will be to repurpose the connectors if they are not mucked up with solder.

Seems that you are not really building cables, just looking to terminate them!  I think I have the same sort of semantic issue with silver soldering which can mean many things.

I have built all my interconnects and speaker cables. I use Bluejeans cable and furutech connectors. Great results. The sound just as good as some high $$$ cables that I had. And yes I sold the high $$$ cables. 

I built all of my power cables with Furutech components. It was a great project and the results were great. I have no idea if it made a difference in sound but I had a great time. I was able to make custom lengths as needed.

No matter what, that "marine grade" shrink tube is the key. You definitely want your wiring to survive a flood.