I'm planning to build a computer with the following components.
Things to keep in mind are that I want it to be upgradable (in the sens that I want to be able to add an additional GPU) and have a good power/price ratio.
1TB Sata III
wo wo wo ... what???? i am using a TP-1500m and that beast powers my stuff perfectly.
And hopefully it will continue to do so for a very long time, especially since Thermaltake is mid-quality but even the "poor" power supplies will work more often than not ootb. The difference between good and bad manufacturers is more just the likelyhood of failure (or how long before it fails).
The experts on these forums are simply trying to steer people to the least likely psu failure, because that is something no one wants to happen in their system.
But to answer anyway, if you want to be safe (and with a beast of a machine like that who wouldn't?) I would start my own thread and ask for advice from someone who knows more than me. Basically other than trusting Seasonic and Corsair I don't have enough experience to give good advice.
To the OP: looks like you're on the right track, take the advice offered on these forums and you will do well.