You’re killing me here. Lack of replacement drivers is a little terrifying.
But it's not that hard to find a few extra. I have 3 extra NEO10s that I found on ebay and a couple of NEO3s (but I know Danny has plenty of NEO3s since I used his drivers).
If you used the BG NEO3s, you'd have to find some spares of those since they aren't identical to Danny's and the crossovers are a bit different to compensate. But again, they do show up on ebay, etc. periodically.
Once built, the chances of damaging the drivers is not that high. Individually, they can take a fair amount of power, and with so many in series/parallel, you've got tremendous power handling headroom.