Is the power supply in my build powerful enough? I think it is but im not sure.
Here is my build.
Also, is bitfenix a reputable psu company?
For a idea on how much headroom you have there is enough for SLI and overclocking everything. Wattage will not be a issue in this build what so ever.
Yes but there is enough wattage for it if in theory the board allowed SLI.
That is indeed a solid PSU. Yes it's powerful enough, that build will rarely be pulling more then 350 watts under typical load.
The Whisper M is a great PSU, and you could use a 550W and have plenty of headroom for overclocking, etc.
Thanks for the feedback.
According to this review, http://www.anandtech.com/show/11123/the-bitfenix-whisper-m-450w-850w-psu-review, "Both units had a voltage regulation of just 1% on every one of their lines and the ripple was minimal even when the PSUs were heavily loaded." So, it should be a good option for you, and keep you at stable voltages.