CaffeinePowered :
Ah, it's a 128 gb, and my copy of W8 was an upgrade over an OEM Windows Vista. I'm actually starting to like the idea of just keeping the original disk separate, possibly even dual booted with a clean version on the ssd.
One of the best ways of installing Win-8 to a new SSD, is to purchase and cleanly install a new copy of it. You probably got the rock low price on the upgrade version for your Vista, so you are not out that much in cost. I would purchase the Win-8 Pro OEM 64 bit version, and using the Personal License Agreement to have MS support, install it fresh on the 840 Pro. Requirements for your system include >1GHz CPU, 2GB or RAM, 20GB of disk space, and DirectX9 WDDM 1 or later. Cost $135. You would then install your retail appls, and then copy over frequently used data.
And if you were going to cleanly install Win-8, make sure the HDD is NOT attached at time of installation, so the OS will install the MS Reserved partition and the System Partition on your new SSD, attaching the HDD later for secondary storage.
As it looks right now, the cost of the MS 8.1 upgrade will be free, if you like the new (or prior) features coming later this year.
If you haven't used a SSD before, you are going to be very pleasantly surprised!