You are going to run the components down faster by keeping it on eight hours than turning it off and then on again later -- not to mention that it'll help reduce your power bill. Power surges shouldn't be an issue if you use a UPS -- and you should use a UPS regardless of whether you keep your computer on or off when not in use. Of the four computers in my house only one is on all the time, and it is a firewall/IP masqurading router/server box that needs to have constant uptime.
"You are going to run the components down faster by keeping it on"
What components "run down"? Actually most electronic component failures occur during power-up cycles. The only negative I can think of is that you are consuming power during on-time but that is a reasonable trade to some. I have 2 computers, three radio transceivers, and other electronic equipment running generally 24/7. I do shut them down when I am going on vacation or long weekends.
Either is acceptable and no one can fault your decision in any event. YMMV