Will a standard fitment fit on a palmetto state AK47?
Yes, PSA AKs are standard fitment for furniture.
Do you make these to fit a vepr-12 or would I just have to modify it?
VEPR-12s use similar furniture to RPKs. I don't make that fitment. Here's a good forum thread I found with lots of info and options https://www.vepr.org/viewtopic.php?f=14&t=5653