Consider this. If you want to be able to easily swap back and forth you'll have to add a new cassette and a new disc rotor to your new rear wheel. $$$$$ Know what I mean?

If you're hard on wheels or race it would be nice to have a spare for when you knock the thing out of true or taco the rim, but I think for most of us the spare will just sit in the garage.

After seeing what happened to your hub i'd be thinking about replacing it with something a little more reliable. What's from keeping the same thing from happening again?

of course, If money is not a problem then I suggest the Chris King hub. I'd probably go with the Shimano XT though, 14/15 butted spokes and Sun or WTB rims built by an experienced builder not a machine.