The psu switch is volts not watts. It's a 275w psu and seems to be a decent quality. You will be fine.
http://www.aryan.es/info/papers/VFYE3510PF091ES.pdf The original graphic card options are similar power. The 610 is 29w, the nvs 290 is 21w, and I couldn't find the exact specs of the 9300ge but it should be ~25w. If the pc is just use for browsing, movies, and other non-intensive tasks then you could go with something cheaper. You can usually find a 5450 for cheaper.