What's the os?
I'm going to assume your ssd supports TRIM.
You wouldn't want to copy everything if you did have room because it would decrease the ssd perf. rather quickly unless you were able to manage all the writes, and you didn't fill it up to/close to/ capacity.
I agree with mrjack. A fresh install is the best, and imo the only, way to go. If it's Windows, copying it certainly isn't best for the ssd as you could loose performance.
7 is ssd friendly, will recognize the ssd and make some adjustments @ installation from disc. 2 examples of things that happens from disc: the alignment of the flash cells are diff from that of a hdd-and the 'format' equivelent for ssd is diff.(altho there are some tweaks that I would recommend that 7 doesn't do)
If you managed to manually do all the tweaks beforehand for your copy, you'd still have a copy and not fresh. If anything goes wrong, and you have to uninstall and/or secure erase, that degregates ssd perf. as well. I can't say 1 time or 2 times or how many times before the loss is noticed,,,I just know that uninstall, erases, and benching it, drops performance a little each time, with benching being the most harmfull of those. So after a few years you want that to be a low number and not chance starting with it from the new get go.
So, things aren't always as easy as they seem. It's well worth the investment of a disc with a reusable license not only to protect your ssd, but for future upgrades or new pc.
EDIT: vista and xp aren't friendly like 7 is, so in that case, allll the tweaks will need to be done manually.