Hi Steve,
The Core2Quad is still a decent CPU.
That said, the i7 3770k or 3820 at 4.5GHz are *significantly* more powerful/fast.
In particular, you'll be able to run substantial loads (glitch-free) at the smallest ASIO buffer size (48-samples in your particular case). You'll be able to run multiple convolution reverbs without bringing the machine to its knees.
If you don't enjoy testing, I'd recommend sitting out Win8x64 for the next 6-12 months.
That's not to say it doesn't work...
But... you're inviting a lot of potential issues with such a new OS.
BIOS updates, core hardware driver updates, firmware and driver updates for audio specific hardware, and updates for the OS itself are all necessary for a rock-solid DAW platform. Win7 isn't going away anytime soon... so I'd play it safe and use Win7x64.
If you plan on running Vegas 12 Pro:
I'd want 16GB of RAM, a video card that'll (significantly) help with processing/rendering, and I'd want newer/faster/larger HDs. If you'll be working a lot with video, I'd also want a BDR for longer-term backup of data.
FWIW, Vegas 12 can be a little flakey (crashes more than X2
)... so I'd definitely recommend avoiding Win8 (for the time being).
For backup of the OS drive, I wouldn't want to rely on Windows backup.
IMO, That's a process best done outside the OS.
Both Paragon and True Image allow using a Bootable Disc to create/restore any backup image file. This is a very clean/lean approach to backup/restore (no scheduling services, etc running in the background).