lol, although this is tech, it isn't computer tech, lol. You might try the board at
www.sysopt.com for a more expertise answer, however, I will give you my opinion.
I leave my PC on 24/7 for weeks at a time and then reboot every once in a while. Your fans will be running constantly, so if you don't like that, then shut it down. I guess it depends on how often you'll be on it. If you're on it once a day, you might just shut it down and start it back up.
My philosophy is, by the time the power supply craps out, it'll be time for a rebuild anyway

If it's in your room, you might consider one of the quiet power supplies and quiet fans. Mine is kinda loud, but I've just gotten used to it.