First I would make sure that you have all your data backed up. Then I would probably make a full system image using something like Macrium Reflect or Acronis. This said, I would not recommend using windows 7 anymore today. Since you will be going to these SSDs anyway, I think now would be the best time for a fresh install of Windows 10. You should be able to activate it with your existing win7 product key. Lastly, I would not use RAID 0 on these SSDs. Though it may increase performance in large sequential transfers, it may have a detrimental effect on random IO.
If you really want to do a clone and upgrade, which I could understand if you have a ton of apps you don't want to reinstall, you would restore the system image to the SSD when installed, using the app you used to make the image, and then you could do the upgrade to win10.