LED lighting that lasts longer than me
What is a resource to use to find superior support components (in
  terms of lifespan) so that I can build my last set of lights such that
  they will fail after I am dead


MIL-HDBK-217f (RELIABILITY PREDICTION OF ELECTRONIC EQUIPMENT) is a good industry standard for estimating the lifespan of electronic components versus various operating conditions and stresses. I use it a couple of times a year and find it very useful for estimating overall MTBF of a circuit.

It's a little bit of a learning curve but worth the effort.

I have also found a calculator that uses the same models as MIL-HDBK-217f here. It only does resistors and capacitors but it might be a way of easing yourself into this sort of calculation. And here appears to be a free downloadable software tool that uses the models of MIL-HDBK-217f and many other models.