SKeen, sorry to learn about your buddy. I'm no longer sure about that theory regarding bibs/waders/drysuits filling up causing river drag on humans. I did some work this past year with some science folks doing research on this topic for the Government (researching how waders might cause drownings). As simple as I explain it is that water doesn't have an effect on water weight while it is in it. You will notice a big effect when you try to lift it above the surface area, but while it's in the water it is neutral. When I saw the data I was shocked, but they did a huge amount testing.
As for drysuits I have been wearing the Level 6 Emperor for the last couple of years and it is awesome for the price. It has about every feature you can throw into a drysuit and it's built serious for a great price. I'm stoked on mine.
Drysuits | Level Six