I think you would be mostly fine with the 16'er and bigger tubes on those runs. Might as well go 16' and give yourself some space.
If it gets too tight, could always use as excuse to get a play boat!
All of those options sound like solid boats to me. I have a '95 E140 as well, love that boat, ran in Cat close to 30,000 and down the Grand at high water this winter, but thinking about some new rubber soon as well, since I don't want to run my raft down to nothing someday. Will part with my left nut before I get rid of it.
Thinking about a large Cat, since I will keep my 14 er for passengers, plus cat tubes are more affordable, and sometimes save yer bacon when you screw up.
We can't always agree, but we can still be civil to each other.