Talk about your 14.0 Trib. Are you unhappy with it?
I ran a 16'er for 5 years as my only boat. It was too big for a lot of I-II rivers and most things under 1,500cfs.
I added a 13.0SB four seasons ago. It's a tad small, but is kind of a sports car. It's great for daytrips with 2 adults and 2 growing kids. The girls are now 9 and 11 (we got it when they were 6 and
16.0SB IMHO would be more apples:apples with the 156R (closer in shape and volume)
For the money, keep the 14.0Trib and add a 16.0Trib.
Buddy of mine has a 143D. It rows/paddles a lot like my 13.0SB.
For "all around", and paddle-ability probably the 156D.
If you go 156D, are you thinking sealed pocket floor or open floor pocket?