I wouldn't count on any color transparency film being around into the future. Color negative is the way of the future. And even it won't be around that long in the grand scheme of thing, in my best guess.
For black and white, I personally prefer T-Max, but Kodak's film division has been doing poorly for many years, so if longevity is the main goal, I would use Ilford Delta 100 or FP4. Or just use T-Max until it is gone, and then switch to Ilford when Kodak goes away, as I plan on doing. Or Ilford could just make Delta as good as T-Max...and start making Delta 400 in sheet sizes again.