Turbo upgrades?

i was wondering what types of turbo upgrades r possible. i was looking for the most power without overkill. I still want a daily driver. thanks

For a healthy turbo that is very streetable, I highly recommend doing a T3T4.

"most power without overkill" is a bit of a oxymoron. :)
There are HUGE turbos that offer "the most power", but they are not very streetable.

thanks what i meant is i want a fast car, but not 1 that can break the sound barrier.