[lo bux racer]

You don't buy low compression pistons for the "someday" turbo. You buy them when you are ready to run high boost, and they are the final touch to the hard part purchase.

Before you spend any money, you need to sit down and figure out what you want to achieve, what you can afford to achieve, and what you are willing to live with. Then buy parts to achieve those goals. You need the goals before you buy the parts...

 

[lo bux racer]

CT-20B. Not a great choice, but workable, maybe. It's hard to say because Toyota doesn't publish compressor maps for their OEM turbos. Again, you make a plan first. Then pick your turbo. If you choose a turbo because it's a cheap thing to acquire, you may be severely disappointed with the results. You'd be far better off to figure out which turbo will provide the boost you want over the range of rpm you need, then go shopping.