If you could build your ideal surround sound mixing room what pieces of gear would you include? How about sound effects libraries? Surround plug ins? Speakers? Monitor controller? Anything and everything!
I would start with the THX specs, and then add from there.
I think gear is not so important. There is a lot of gear out there that will do an excellent job. The most important thing is the room itself. I would therefore also start with the THX specs. Sadly the room is probably not only the most important but also the most expensive thing.