Yes, but for now the only way to say the field exists is to find the particle.
Quite so, of course. The theory ties the two together.
Showing that a Higgs boson exists, which is what the supercollider experiments appear to have done to better than 99% certainty (with a small but measurable bump in the aggregate collision products data) gives credibility to the existence of a Higgs field.
... but the Higgs boson itself probably won’t be anything that modern technology ever uses. It pops back out of existence so quickly that there could not be things like beams of Higgs bosons.