Are you after custom or out of the box so to speak?
Miltek are rated highly on here for the 'out of the box' ones
I have a longlife custom turbo back on mine
There are lots and lots of versions from the likes of Scorpion and Jetex etc all comes down to if you are doing it for mods or looks/sound.
Unless you plan on going for a turbo bigger than a K03s then I was told 3'' isnt needed