Advice and recommendations?

Two drafts in, it seems I can't avoid a fairly lengthy post! I've left out what I can for now and will add more detail if needed.

I'm looking at my options for a couple of systems where I need to add or substitute a power supply.

Assuming I move the current supply to the older AMD X3 system that will shortly be rebuilt, I'll need a new unit for the box with the following spec:

Intel i3-2100
Gigabyte Z77X-D3H motherboard
8GB RAM
560 Ti graphics card
Xonar DS sound card
3 internal hard drives
DVDR drive
A mix of self-powered USB external drives, mice, keyboard and occasional use of a 360 controller.

Nothing too demanding, then.

It's currently running wonderfully on a Corsair CX400. With few options that meet my requirements, I keep narrowing in on the 520W Antec High Current Gamer. Including financially, I'd hoped for something more modest but it has seemed the better choice when, for example, it comes to the cables and the fan - all at a 'reasonable' price.

Some wariness built from comments on its older group-regulated design, but I wonder if that's going to be relevant when the supply won't be under any great stress. Would cross-loading really be a point of note in a system such as this or is it more for the extremes of review tests?

Until the late discovery of the 600W Silverstone SST-ST60F-P Strider Plus (more costly and carrying an unnecessary spec), XFX and OCZ looked to be the next best - but the cable-count and length isn't ideal and I have reservations on support if the supply fails. Beyond knowing the name, Silverstone are an unknown to me as a company and in terms of the reliability of this Strider Plus PSU, this would be the same for me in that regard.

The CX400 used to power the Athlon system and I am happy to buy a lower-capacity supply for that box if anything can be recommended. Nothing has looked brilliant so far. Though I now have a 9800 GT graphics card spare, I'll probably be using the on-board graphics here and it'll have the usual few gig of RAM, a hard drive or two, one DVDR drive and the same mix of external bits as above.

These computers are likely to run for long durations. One of them will run 24-7 for about 360 days of the year and the second could be up between many hours and a few days when not set to rarer long tasks. Partly with the long-term use in mind, a ball-bearing fan has been a part of my tentative spec requirements.

A supply that can be considered quiet is important. Anything that helps with the build would be good, though I'm fine with captive cables. The two cases that I have mean that it's hard not to make a clean build, so modular cabling doesn't hold a great draw for me. If there's a PSU with unwieldy or inflexible cables, that might be an option to drop however. I struggle with some physical difficulties and though building a PC is a thankfully rare occurrence, it can be difficult to do and I appreciate it being helped along by good cable routing and long, flexible cables. The modern trend of wrapping PSU cables really helps there!

Oh yeah, looking ahead, upgrades will be unlikely or modest. Internal hard drives may be added, an i5 might replace the i3 or another card might take the place of the 560 Ti if it became necessary, but the demand on the power supply wouldn't change much.

I think that might be enough for now!

Thanks, guys.