For the Iraqi, I prefer the FOW egyptians, they are better in my humble opinion. Said that... I have also PP painted as Iraqi. I used packs 62, 63, 65, and 60 from the AK47 range.
for the Iranians I do not think Vietnam war americans are any good. The main weapons were the German G-3 and the MG-3 and they tended to look more like West German infantry with desert themed uniform. QRF or FOW modern west Germans are the best, if not the only, choice here. From the AK-47 maybe you can steal pack 37, but other than that I am afraid the only option would be using the professionals with head swaps... for a decent size force it is a chore, and still you will not have the MG...