Yes been boosted for a while now.
3SGTE Caldina/Celica/MR2 rods are straight bolt in (Eagle ones seem popular), as are 3SGTE Head bolts/studs (ARP), conrod and main bearings (ACL Race Series)
Piston bore and stroke etc all the same from 3SGE to 3SGTE, only the standard 3SGTE Pistons lack about 10cc of dish from the top and the valve cuts are on a different angle. (Just any forged piston maker and a good engine builder to do the machining)
3SGTE Forged pistons are ok as they have dish to compensate for high lift camshafts, but angles again need to be machined correctly.
Head depends on how far you want to go, if your keeping it VVTI I would just recommend getting a quick port and polish to free up the movement of air.
Cranks are fine as they are the same ones in the turbo vehicle anyway.
On a stock (untouched) 3SGE, you can do up to 12psi if you want, but safe on about 10psi as long as you get your fuelling right, and a good tune (retard just enough ignition timing, injector correction and flow etc etc)