What speed velocity would this kind of travel take?
The best you could hope to achieve would be some "large fraction" of the speed of light, so that your trip time would be comparable to the light travel time, so we're talking generation ships, or suspended animation here.
I saw a paper once years ago ( like forty years ago ) that outlined the payload for an acceleration and deceleration to and from .9c . It was ridiculous. Assuming conversion of fuel mass into pure light-speed propulsion, the payload was something like 1/100,000 or whatever. Very discouraging!
Interstellar ramjets? At "gamma = 2" or .86c, it costs as much kinetic energy to scoop up a particle as can be gained by ejecting its rest energy as photons, the theoretically best propulsion efficiency.
... Corrections cheerfully acknowledged !