any computor will work at first. as you progress,you will want a better bike and a better computor. match the eqipment, no need for a $100 computor on a $100 bike.no ofeence intended,I have no idea what a sirrus costs. but you git the idea. I have a sigma 1990 with docking station to load all data to my home comp. it even come with a heart monitor strap. as for acuracy of distance. make sure it is calibrated to your tires. any discepancy will be great the further you ride. ride safe! but ride!