Hi, I would say 1kw PSU is about 3x too much!
I've run my PC, i7-2600k @ 4.5GHz + GTX560Ti from a Seasonic S12II-330w PSU. My estimate is it draws ~280w DC, and at least 50w less run at stock speed. Ivybridge also uses less power than Sandybridge and your proposed Radeon 7870 is similar to my GTX560 Ti in power usage.
How about using Seasonic X400 or X460 fanless PSU? In Solo II can mount it with vent up so heat free to rise out of PSU and case and I doubt you'll push it beyond 250w DC load anyway.
Unless you over-clock the CPU a lot and go for a bigger video card, or two. In which case even a Seasonic X-560 will be enough power. In silent mode the fan won't run at low loads and should be quiet even under high load.
Enermax have a new, expensive 80+ platinum range, Platimax. In 500, 600, 750 and up to 1500w. Discussed here.
The 500w has a reduced cable count so I might pick the 600w version as it's barely any more money, round here anyway.