Nether... Get P mags
Why in Sam Hill would anyone ever go purposely LOOKING for ProMag or Thermold???
I accidentally picked up a couple at the gun show where I got my AR before I knew any better and as soon as I got to looking at them I just gave them away.
I have all USGI 30 and 40 rounders. I tested the 40s out last night and thye seem to work just fine.