"Did they ever find the bodies of the two soldiers who fell into the river with full packs on and were swept under the water? "
Yes. There are no more MIAs or Whereabouts and Duty Status Unknowns from this conflict.
Fox news has a complete list on their web site.
"Did they ever find the bodies of the two soldiers who fell into the river with full packs on and were swept under the water? " Those Marine Seebees didn't fall into the river. Their goal was the enter and wade across the river to achieve an objective.
From what I read, due to the weight of their equipment, they couldn't keep afloat and drowned.
Yes their bodies were recovered.