Which turbo is better?

I'm am thinking more to which turbo is better. I own an 91 Supra turbo and one of my friends is selling his CT20B. I am wondering if the CT20B is better than the stock CT26 on my supra. If so, I would probably buy it. I am also wondering if I would need to buy a kit to make it fit or will it already fit in my supra( What I mean is that just take out the CT26 and add the CT20B without any other modifications).