Home Server PSU

[enigmo]

I'm looking for a recommendation on a PSU for a large home server. I've currently got an old OCZ 600W PSU, but between drives and fans voltage is being split to hell and I'm not too confident in another round of splitting next time I drop in a drive. That and there's a bit of static buildup that makes me worry insulation somewhere is failing.
A PSU calculator I used recommended a 500W PSU (http://outervision.com/b/mmpjlm), but there are a couple of things to bear in mind:
It's on 24/7, so Gold or better efficiency at lower draws would be nice
The SATA requirement for drives and 4-pin requirement for fans is large (16 and 5 respectively, so I know some splitting/chaining is required, I'm just looking to minimise that)
It's a big old case, a CM Stacker 810, so cables need to be long enough to be routed neatly from top rear of the case where the PSU is to bottom front, where the furthest drive and fan live.

So, nothing complicated, just the moon on a stick. I've not mentioned budget as I don't have one. If something is perfect, it's going to be used 24/7 for years so I'll spend the cash.
Ta!

Edit:
FYI, ones I'm currently looking at after some brief looking:
Seasonic Prime 650W Titanium
EVGA Supernova G2 650

 

[enigmo]

Cool, ta all. I am aiming for a lower wattage PSU. In spite of a lot of drives, I figure I'd need a few dozen before the watts there make a difference,

 

[enigmo]

I put a superflower 550W golden green in mine. Not quite as power hungry as yours but still runs 7x WD SE disks via an intel sas expander and lsi sas controller.

Actually, under the hood, that Supernova is a Superflower and gets some excellent reviews, so definitely worth me concentrating on. Thanks!