I had not given a lot of thought to the weight issue.Less unsprung weight is always a good thing.I'm somewhat surprised you could actually feel the difference!
I was sort of hoping they were 15" but alas you were correct that they are 14's.There really aren't any good tire choices other than the raised white letter type commonly used on vintage American cars (Radial T/A,Dunlop GT,etc..)
I may keep the bundts and try a 225/60/14 tire.The 205/70's available these days do not have the relatively stiff sidewalls like were available when these cars were new.
I have seen a number of cars around my area with newer wheels in 17 to 20 inch sizes.I'm just not a fan of the "clown car" look at all!