If this is your first time owning a turbo charged vehicle that you plan to modify I do not suggest you turbo a ka. Too many things to take into consideration when "slapping" a turbo on a naturally aspirated engine. So many different ways to get the car running correctly, making power and not exploding. Add the bumps in the road of all the after market installation procedures for supporting modifications and its a pain in the ass. I constantly tell people to get an sr20 because for the norm, its simpler, easier, and a proven engine, so why not?
But if you want to experiment with piecing together your own turbo kit, temporarily ghetto rigging things so you can drive the car, constantly maintain fixes that you have done because you dont know the proper way to install them, fight having a shitting tuned piggy back with all or nothing power. Then try to fix your mistakes with something that is supposed to be better which turns into more of a cluster fuck whether it be a standalone method of tuning, turbo swap, or upgrading parts.
Lets put it this way, if you dont learn and fix problems with a turbo car shit is going to explode in your face and your going to be back at step1 with something that dose not drive. get an sr20.
theres a little advice from someone who has had a turbo ka for almost 2 years.