If I wanted to make my own speaker cables, is this a good choice for wire?

Ok then, nice set-up. I did ICs with the previously linked 16awg Jupiter wire, and with Duelund 20awg, both have nice tone and are pretty good overall but are  bettered IMO by my Furutech u-p2.1 ICs.

For SCs, with 100wpc, and depending on the length of your run, you might like the larger 12awg wire mentioned by @needfreestuff .  Duelund makes a twisted pair 12awg in a single cotton casing, just like the 16awg you were looking at.  However if you are trying to buy just one wire to make both SCs and ICs then either the 16awg Duelund or Jupiter would probably be best.

Use connectors from pure copper or silver when possible - plating over the copper/silver is ok. For bananas, the KLE plugs that @williewonka likes should sound nice.  Good luck

I used these BFA connectors in my last build. Crimp and solder.

https://nerveaudio.com/product/silver-z-plug/

Nice work, diy can be an excellent option and parts connexion has some great materials. 

As interconnects, why would you opt for side-by-side 16 ga. wire?  Are you unaware that opens up a world of RFI/EMI pickup?  The Jupiter wire is twisted…a better choice for unbalanced ICs.  For speaker wire, the Dueland might be fine at lengths up to 4M.  Beyond that, maybe go heavier.  For shorter, no need.

The problem with bananas, RCAs, and AC outlets has always been the need for a spring type elastic resistance, which copper is not very good at because it is a softer metal that deforms upon repeated loadings (i.e., plugging in and unplugging).   This is why most bananas, RCAs, and AC outlets are commonly made from an alloy of copper, which of course will be less conductive than copper.  Tellurium copper seems to be the best at about 93% of IACS (Copper is 100-101% IACS), while other alloys sometimes have much lower conductivity like Phosphor Bronze at 19% IACS.  Spades are different since they are actually connected by mechanical compression from the binding posts and have no need for elasticity, which is why it is not uncommon to see pure copper spades.

Interestingly, I thought the KLE bananas used to advertise being silver plated pure copper but after reading the technical write-up in their brochure, it was not so clear to me.  There is a lot of dancing around and referencing IACS but I did not see anywhere that they came right out and said exactly what the pin material is made from, except that it has silver plating and is apparently above 100% IACS in conductivity.  I am sure they are very good, but I get skeptical when I read a technical description that appears to dance around the subject.