I wouldn't change to a undersized crank pulley. In those days the only usable pulley was the mythelogy one because of the dampener it came with. I recommend you keep the stock pulley otherwise the engine will rev fast but the car doesn't move much. It's annoying.
As for cam, use a billet one. Try not to go for those regrinded cam unless it's a proven one. I haven't been keeping in touch with cams but I had a Pipercam billet cam back then. Doesn't make the idle rough and power band was quite broad starting from 3.5k rpm.
If you're going to change pistons it means a full overhaul. You might as well get the head ported by a proper shop too who knows their stuff.
https://www.mudah.my/4G15+Supercharger+kit+pnp-81973531.htm
Supercharger for 4G15. But you'll need a ECU to control the airflow. If you're gonna do this I recommend pistons and a standalone ECU. Gonna be expensive but at least you don't have to register the engine.