The real Sword ones replicate the 7.62 caliber AKs, so an older type of 50s weapon. The VFCs are copies of the 5.45 version so they sync with a 70s and onward time line.
I've seen both back to back and would be happy with either. I can't name specific places to get them off the top of my head but if you browse the retail and classified sections you should be able to find what you need.
For a bad guy setup either version would be OK, but if you're very specific about the time frame or location you should check the history books and then tailor your choice.
Airsoft, where nothing is hurt but feelings.