From Shinma's links, the Intel cpu has more computing power, but if you're going to be gaming the video in the AMD is likely to be better. That said, there are different levels of gpu in each manufacturer's cpu lineup, so some investigation of the video component in each would be a good idea. I would also factor in the cost of the motherboard each cpu would use and look at the total cost. It appears that the AMD cpu you chose is only a single core. For those times when you're multitasking, a single core is more likely to get bogged down.
You're not likely to need much psu power, and a 350 or 400 watt unit from a reputable brand should do. I would look for a Corsair, a cheap Seasonic like the SS-350ET, or an Antec made by Seasonic. If you're patient and look around you can find deals. But pay more attention to the manufacturer than the wattage number. And to find out the actual manufacturer and get a feel for what's good and what's not, read the psu tests at jonnyGURU.