i Bought an alpaka forager, its the biggest packraft I could find. 14 pounds, I added a carbon fiber paddle. It has a load capacity of about 1000#. Two people fit in it fine as well. I used it to float myself and gear across the river, ideally I was going to use it to float meat down the river. But, I did not kill anything. The forager is a self bailer, meaning water comes it, it drains out the bottom. Also means that water can come up inside the boat. They make a bucket boat version too, water comes in, it stays in. For whitewater I had to have a self bailer.
There are packrafts out there that are around 4 to 5 pounds.