No need to sound the alarms but I noticed that my Western Digital external disk (Custom Enclosure) clicks when the read/write head leaves the platters. Any ideas? It's quiet as mouse while reading and writing, but makes the very faint clicking when its idle.

Also, as said by the thread title.
It's time to upgrade, I've been looking at some options:

• Build my own FreeNAS box and buy X amount of HDDs to fill it. (No server knowledge) [However I want to monitor all the hard drives being used; cost??]
• Buy a pre-built NAS box and buy X amount of HDDs to fill it. [I get to monitor my hard drives, but reliability???; Cost: $$$$]
• Buy a crap load of single drive enclosures, buy X amount of HDDs to fill it, and buy a USB hub to hook it all up. [Sounds like that'll cost me $$$$]

This isn't a project that I'll be building overnight.

I already have another project that I'm getting ready for and that's a custom built modular electrical box with surge protection. -- A little cheating on the surge protection part.

One click at startup should be ok, My samsung drive does that. WD drives have a mechanism which parks the heads off the platters in a cradle of sorts when powered off, so I think the click is them getting "back on."

That click I'm aware of. It's more of a buzzing click. And it only does it when the drive is idle. It doesn't do it while seeking which makes this a hard one to track down.

Also I've noticed this for the longest time but GFX cards "seem" to always be mounted upside down with the Fans/heatsink on what becomes the bottom of the card

This seems to me to trap heat and thus makes it harder to expel, that is unless you have a blower type that exits the back.