Your first line of defense and the strongest against flats is the tire, therefore find the most flat resistant tire you can find.
The Tannus tire is a bit of a pain to install, watch this:
View: https://www.youtube.com/watch?v=mm37lyRcVBU
One of the comments was this:
"Yeah, these aren't that simple. Even after verifying all of my rims' manufacturer measurements and using a caliper to do it myself, the suggested size I purchased just flat-out won't go on the rim. They don't easily seat themselves on the one side first like in the video, they will always pop out while making your way around the rim, and they are just too wide to fit down into the rim. Thought these tires were too good to be true and I'm turning out to be right. Here's to paying that much for tires then paying some other dude to try to put them on as well. Not worth it." Then watch this video for more negatives about these tires:
View: https://www.youtube.com/watch?v=9NGNxhJ588Q
Also with the Tannus tire if by some slim chance you break a spoke you have to cut the tire in half to get it off the rim and thus destroying the tire. However, if you're willing to put up with the hassle of installing them or just a bike shop do the install then I think this may be the tire for you since there is no chance of it getting a flat, and they're light in weight compared to a robust tire with a tube. One of the complaints on the reviews was that the tire rode to hard, problem with that statement is that Tannus makes 3 firmnesses of tire, soft, regular, and firm, but the reviewer says nothing about which tire he got.
If you prefer a tire with a tube then the best are the Schwalbe Marathon Plus, combine that with a Panaracer FlatAway liner, which is your second line of defense and the second most important against flats, with those two combined all your flat worries will be virtually gone.
Flat sealants don't work all that well for the most part, the Bontrager TLR Sealant seems to work the best of all of them, but like all of them you must put more in about once a month in dry climates up to a year in humid climates.
Over all for your situation that Tannus tire looks promising.