Which Seasonic PSU?

[IndustryStandard]

This question was also posted in dottorrent's excellent "The Power Supply Unit tier list." here:
http://www.tomshardware.com/answers/id-1804779/power-supply-unit-tier-list.html#12019045

I'm currently shopping for a PSU.

This is my planned build:
http://pcpartpicker.com/user/IndustryStandard/saved/2Lf...

I'm looking at this
http://pcpartpicker.com/part/seasonic-power-supply-ss75...

or this
http://pcpartpicker.com/part/seasonic-power-supply-ssr6...

I may SLI or CF in the future (not yet completely decided on GPU). Which PSU would you guys recommend?

I have Amazon Prime, since that affects the price slightly.

 

[IndustryStandard]

Thanks for the reads everyone. Randomly saw that the SSR-650RM is on sale for $69.99 after MIR. Decided on that one for the price difference.