I did just this using
http://www.partition-tool.com/personal.htm
1. Resize your big partition using the above to something smaller than your SSD, say in your case 80G.
2. Do a partition copy of said partition to your new SSD where you will be left with a 80G partition on your new SSD probably on a drive now known as 'g:' or 'h:'. Either way it won't be 'c:'. Use one of those external SATA/USB interfaces
3. Resize this partition on your SSD to the max of your SSD.
4. Now put the SSD in your machine and remove the big disk and reboot. You will get an error about cannot boot from 'h:' or whatever.
5. Either pay to use the full blown version which outside Win (as a bootable CD) will allow you to change the SSD back to 'c:'...or insert your original Win install disk as it will sort it out as a repair (well Win 7 did no probs).
Using the above software be aware I had to reboot between stages to let the effects take place. I am sure Acronis etc can do it but the principle is the same.
I may have missed the odd step like activating the new partition but it was a few months back.