life, if that temp is max, a long time. Before a CPU dies, it tends to be replaced due to it being so out of date, the CPU is quite a durable components and lasts quite a long time.
Good choice of motherboard, Mobo's don't increase/decrease gaming performance, the more you spend will be the OC (Better chipset the better OC, with the highest Chipset, the better phase design ect..meaning higher OC.) More features and better multi-GPU support. Don;t worry about the motherboard but more about the graphics card/CPU and least of the three, ram.