Real world swap cost

My biggest concern is I only have a preconceived notion what it would be like to drive a 4 speed car.

I think untill I find someone who'll let me drive one even a slant 6 car I'll have to hold my tounge for awhile.
Smart move. Don't mess up 340 cars. You cannot swap to a 4-speed without cutting and welding, and it will easily be noticed come resale time.