The banshee motor is a low compression motor (even after you mil the head, unless you have a crazy set up) Forged pistons are not needed,
They are heavier than cast,
Take longer to worm up
Expand upon worming
shorter life span than cast.
But they will hold up to much higher compression than cast
I have had good luck with Vertex Pistons, they are ceramic coated. which runs more efficiently and last longer.
I milled the head on my banshee and i am running about 10:1 compression (fairly low compared to my other bikes, they have wisco pistons)
I found that shaving down the dome on the vertex piston.