I've developed an n-body orbital mechanics simulator that allows you to explore the solar system with a propulsion system of your choice (Saturn V, Falcon 9 and so on). The orbital state vectors that I use for simulating the orbits of the planets and their moons are obtained for JPL, and it all works pretty well provided you employ a time step that is appropriate for the system being simulated. You can perform a trans-lunar injection, hohmann transfer to get to Mars and so on.
Now, I've heard that a planet has been discovered around Proxima Centauri and not knowing any better, I would of course like to simulate a mission to this planet with a propulsion system of immense power that I have dreamt up with little concern for what can actually be achieved (toying with the idea of using the sun for a gravitational sling-shot, although I'm way too ignorant when it comes to orbital mechanics to know if this would actually work out, disregarding the fact that no known materials would survive the heat and tidal forces a spacecraft would experience in such close proximity to the sun).
Problem, though, is that I don't have any state vectors for the centauri system... You know; x, y, z, vx, vy, vz. Nor do I have state vectors for the path the bary center of our solar system takes through interstellar space. Any chance somebody could point me to a source containing these vectors or alternatively a way to calculate them from the stellar catalogues that are out there (haven't been able to find such catalogues with vector data, but then again I might have looked in the wrong place, in which case I apologise for wasting your time)?