Welcome to the site, I'm fairly new as well. If there is anything I have learned here, dont skimp on your psu. You want quality. I've used
THIS SITE to help me decide on how much power I need. Tbh, I know a lot of people that put too much emphasis on more power (1k watts plus) when they are only using 650w. Sometimes it's better to go with a better quality and go with a 750 or 860 psu.
Anyway, check out that link and it has a lot there to help you figure out how much power you need.
Also, here is
A LINK to verify that the psu you are looking at is the 80Plus Certification that they advertise it as.