Bitcoin supply will not run out as long as there are traders who are willing to buy and sell it will continue to circulate in the market. Mining cycle of bitcoin may last until 2040  but as times goes by the mined bitcoin become lesser and lesser because of dificultty or halving that being set by the developer. And fir xrp and eth i would pick eth since xrp is centralized and majority of coins are being kept by the developer.