Mac Pro 3,1 - did my hard drive die? And what should I replace it with?

Question

Hi,
I inherited my late husband's 2008 Mac Pro (3,1 model) which had 2 x 500GB hard drives in it and 6GB of RAM. I filled the remaining hard drive bays with 1TB drives (I take a lot of video so needed the extra space). The boot drive was partitioned 50/50 in Boot Camp. I've upgraded the RAM to 10GB and I am currently running Lion.
Today, while doing something as innocuous as scrolling down a web page, the bottom half of my screen went black and the top half began flashing wildly. When it  stopped after several seconds, the mouse would not respond and I could not click on anything. If flashed a bit more, and then I had mouse control back but could not click on anything - web links, applications, finder. After waiting patiently but getting nowhere, I powered the machine down manually, and when I re-started it, it failed to boot. The chime sounded, the apple appeared, and the little revolving wheel, but at the point where the screen would normally go blue then display the desktop, it just went white. The fans spin, but otherwise it's very silent.
I tested with a second display, got the same issue. I tried booting to recovery mode but it went back to the white screen. I could start in target mode, and there were no issues with flickering screen, so I don't think it's the graphics card. Then I tried browsing to the hard drive over the network, but it wasn't showing on the PC network page, nor could I connect to it via the home theater system, which I can normally do as the streaming app launches on start-up. I am assuming this means the drive has failed? It's the original, and we bought the machine when they were new to the market, so is a good 5 years old. It contains not only the boot drive but my documents, photos, websites, selected videos, all of which are backed up on the Time Capsule, and I was in the process of uploading to cloud backup as well (although not very far along, due to data cap and slow international upload speeds). I had no warning it was about to do this, but then I guess sometimes you don't!
Assuming I need to replace the drive, would it be worth replacing it with an OWC Mercury Electra 480GB SSD in an Icy Dock sled? Or would that be overkill for such an old machine? Would getting a standard 7200 WD Caviar HDD or similar give me enough of a speed boost? Obviously I am rather enamoured with the idea of a blazing fast SSD but I'd have to import it (not available locally) so I don't want to shell out all that money unless it's really going to make a massive difference.
Is there anything else I would need to know about using an SSD over a HDD? I assume I would fire it up the normal way - install it, boot from my Snow Leopard install disc (I downloaded Lion from the App Store) format it, clean install SL, then re-update to Lion, then restore my Time Machine backup? Am I likely to experience any weird issues due to it being an SSD? I see talk online of firmware problems and something called TRIM that I don't know anything about. If it's most likely that I can install it and rock on as normal, then I'm pretty keen, but if there's a reasonable probability of it being temperamental, I probably wouldn't be willing to deal with that (and therefore go the HDD route instead). Therefore I am very keen to hear people's opinions and experiences.
Sorry for the terribly long ramble. The more I have researched this, the more questions it raises! All advice gratefully accepted. Thanks!

Answer 1

more than likely it is your video card. If it is ATI 2600XT, tell it bye-bye. The card is barely used at all in TDM or Safe Boot Mode. The 2600 and Lion and the issues with that card, even if it seems okay, is not.
Depending on Windows OS as to how it mounts and sees your Lion HFSX (there is a nice HFSX driver from Paragon, and an NTFS driver for Lion too)
480GB SSD is overkill for any system unless you are pushing CS6 2-3GB images and then for scratch. All you need for a boot drive is about 100GB.
If you have an SSD now, then 1) you need to do a full image backup and restore (regularly as maintenance), and 2) TRIM Enabler
Save Lion and you can always do a clean Lion install w/o going back to SL - but you might want to keep SL (dual boot) and handy if you run into anything you still need that required PowerPC/Rosetta
FBDIMM RAM dies, Amazon has $32 kits of 4GB. And having all 8 DIMM slots filled improves things. If you need or want to and feel 16GB isn't overkill.
SSD and issues are always possible. you should not just go along. not without a clone image. And you should have another drive w/ TRIM Enabler so that you can do a repair and "trim" what is needed.
Clone a system with CCC regularly. Bootable. And can also be used by Setup Assistant.
Install Lion over a heavily used SL system and there are likely remnants of old things that get in the way and left in there and not removed.