Did you guys know that 85% of statistics are made up on the spot?

To your question, if you want to run concole games on your cab, there is nothing to stop you. PS1, N64 and even Dreamcast emulators are pretty mature at this point even if they run higher level emulation than say, MAME and you can play most games without problems (pSX for PS1, Project64 for N64 and NullDC or Makaron for Dreamcast, see
NonMESS for details).
As for controllers, there are plenty of options. You can go as cheap as getting a pair of logitec USB PS2 controller knock-offs or get fancy and go wireless. There are plenty of PS2/Gamecube/XBox to USB adapters out there.
I set my cab up for NES, SNES, N64, GBA but when Wii Homebrew came of age, I switchid all of my console emulation to the Wii and the cab is now basically arcade only. However, N64 emulation on the Wii is not there yet.
If you enjoy them and don't have another suitable platform, you should go for it.