I think certain religions such as Mormonism posit the idea of living an afterlife on other planets but your philosophy is certainly unique. Buddhism teaches that a soul can advance to the point where it no longer needs to be reborn and can thus escape the endless cycle of death and rebirth. But having said all that I personally don't believe in the idea of reincarnation or karma and the related teachings. But in trying to develop a plausible story line for fiction you'd have to try to speculate and work out any major inconsistencies. Some things I hold lightly and am open to but the whole Buddhistic system of reincarnation I absolutely reject. Mind you, I am a born-again Christian but that entire system of eastern thought has never resonated with me.