Don't do it! If "max" is part of the name of the PSU, it is either a reference to the number of components it will take with it when it dies, or the extravagance of the pyrotechnic display.
Something like an Antec Earthwatts 650 would be good, or something from Corsair, Seasonic, or PC Power & Cooling.
Enermax could well be the exception that proves the rule. They are also generally well-reviewed, especially their latest models.
Sites that do quality, competent technical reviews of PSUs (including load testing, waveform analysis, etc) include www.jonnyguru.com, www.hardocp.com, www.hardwaresecrets.com, and www.xbitlabs.com. All use high-end equipment for load testing. Jonnyguru and Hardwaresecrets also disect them to tell you Why they got the results they did.
Fill in the blanks as best you can to come up with a rough estimate of power requirements for your particular configuration. Please bear in mind the results will be overestimated because there are a lot of cheap, low quality psu's of questionable reliability that people insist on buying.
Seasonic, Corsair, and PC Power & Cooling offer high quality power supplies that are very stable and reliable. They consistently earn high marks in technical reviews and comparisons. They're also the three brands most often recommended by veteran posters at this forum. My personal preference is Corsair.