"I guess I have two questions: (1) does anyone see any glaring flaws in

this plan; and (2) Verrry roughly, how much would something like this
cost? "

I would relook at the options and figure out a way to avoid having a
small 16" sink. It's very nice to have a dishwasher, but I sure
wouldn't want to get one by going from a 31 inch std size sink to a
midget one. This will also have an impact on your home's resale value
and will be easy for anyone looking at the house to see. IMO, by the
time you're done, if you put in a small, non-standard sink, you will
have decreased the home's value.