boot drive recommendations

I booted from a single 8gb thumb drive somebody gave to me for years without any issues. When it failed, I switched to a 32gb transcend thumb drive. It failed the first time I updated my nas. I recovered again, but again it failed the first time I updated my nas. I don't know if this is simply a crappy brand thumb drive or whatnot, but I won't be doing any more upgrades until I better understand what is happening and implement a solution. I currently have the following issue:

Boot pool...

boot drive recommendations