Would it seem impractical to set 2 ssd card in raid 0?

I've been thinking about my upgrading my computer with another ssd so my computer can run faster and to store most of my games, but the problem is that I don't really know a lot about raid 0 or how to setup raid, and the only thing I know when setting up is that I have to reinstall my operating system. Is this true? and is it gonna cause any problems if I am to have different sized ssd (like having a 128gb and 256gb ssd)? because I know that it's okay to have different sized hdd in raid?

Edit: If you're wondering what ssd card I have it's the Crucial M4 128GB.