The quick answer to your logic question is - no. You won't need logic on each machine. Kontakt works or you can use a cheaper/lower overhead host such as V-stack or Bidule.
Here is the best forum for asking your questions in regards to everything dealing with orchestral sample libraries and such.
http://www.vi-control.net/forum/view...41de0ba9d4af34
Here is the site for a member of VSL's forum who was an early problem solver with setting up mac mini farms.
http://www.createfilmscores.net/?page_id=9
VSL's own forum is also a better source of info
http://www.vsl.co.at/en-us/69/128/33.vsl