Perplexed in Peoria wrote:

One problem with this idea though.  What to use
for energy?  Fissionables probably can't be found,
and I suspect that fusion fuels may be exhausted
more quickly than you can hop to the next comet out.

I'd expect there to be lots of hydrogen and other light elements on the Oort bodies. If we ever develop fusion, we'd have enough energy to use them.