I think you def. need a variety of pins from all eras if possible. I understand having limited space and needing to choose what appeals to your tastes.
But there have been so many awesome machine from all eras that you kinda miss out on the game play. I have stayed to the SS pins, ranging from 79-2014, but keep contemplating on one EM at least. Went to Allentown where I got to play a large variety of EM's that I never did before and they were a blast.
Also If you are into competitive play, you will def need to brush up on the older pins. I have seem some truly awesome players on DMD machines, absolutely collapse on the older pins.
Just my two cents.