I would go forged.
One thing to keep in mind, which I say this to anyone who is looking to build an engine, do a cost comparison before buying parts. With using you current block, it will need (at the least, in my opinion) to be machined, hot-tanked, re-bored, re-honed, new oil pump, freeze plugs, etc... plus your stock crank will need to be re-ground and re-balanced with your newly bought rods/pistons. Adding up all that, it might be worth while to just buy a new short-block ready for your heads/intake/turbo and dropped in your car. MMR and I'm sure some other reputable builders have short blocks built to handle the power you are looking for for about the same amount of money as what it will cost to do the above (and without the hassle and inevitable headaches that come with piecing together an engine)....just something to think about...
As far as cams go, why not do it right and get custom ground turbo cams...?
Matthew 26:52-54 / Go Pack Go!
1987 Mustang GT Hatchback - 2V Mod Swap In The Works
1997 Lincoln Town Car, PI Intake/Cams, Sofa-On-Wheels, "Fat Tony" we call it
2001 GT Convertible - D1SC / Geared / Cammed / 440wh 400wt - TOTALED 2/2019