Wow! Sounds like a lot of fun to do the research and planning, even!
Questions:
Can you include restaurant meals in the allotted budget--For example, michelin starred restaurant in Paris (or wherever)?
Can guided tour experiences that are booked separately from lodging be included, like a private, after hours tour of the Vatican or Lourve?
Have you considered the tax implications of the win? For most of us, a $20,000 "value" trip will result in additional income taxes of as much as $8000.