Thanks for the insightful response. This is exactly why I came here. Given my lack of experience, there are probably many things I haven't considered. I had a hunch, however, that asking for a "1999-2013 machine" might be asking for the impossible.
Given that I took your advice Tanooki, and split this project into two separate machines, how would you proceed? What would the two machines look like, and what years would they cover?
I would really like the machine #2 to go up to at least 2013 and play these games well (on best setting, not medium)
What do you think?