It's important to purchases a good PSU. This power supply can last you 4 - 5 hardware upgrades. I'm personally still using my ST1000 Silverstone 1000w PSU for 5 years. Keep it clean. Use a battery backup and it should last.
No there isn't. There is an influx of media coverage of the Titanium rating, but a single new Titanium PSU from Corsair (the two by Super Flower are 2 years old) isn't exactly what I would call an influx.