If you are talking about the Samsung 830, on sale at NewEgg, I would say buy it now for it is indeed a great deal. Keep in mind that deals like this and further sale drops are bound to happen over time (especially with the current trend in SSD price drops and lack of regular HDD availability), so fret not if you find a deal slightly better in the near future. For now, it is my understanding that it is a great buy (~$0.75 per GB
); I myself bought one today.
Now as to your other questions, I believe there is a software called "Norton Ghost", as included in Samsung 830 desktop upgrade kit, which allows you to migrate your system files from original HDD onto the new SSD. I am not too sure on the technicalities of this, as I myself am new to SSDs, but I hope this helps. Also, if you do not have the disk, but assuming you have a legit product key, why not just "obtain" the Windows 7 installation file and burn in to a CD (from friends, whether in person or over the net :|) and then follow up with using you own product key when prompted for it during installation?