It should be a goal for Earth to send a probe to one of those stars. As the probe will be unmaned, a mission taking a hundred years or more is not out of question.
some combination of nuclear radiation and/or solar seems like it would fit the bill? 100 years is within the useful range of a large radioisotope generator.
Solar would not work when you're out past Uranus or so, and the Sun is just a bright star with barely a visible disk. There's simply not enough sunlight out there, and you won't get enough light from your destination(s) star until you're similarly close to it.