Buyers and Sellers of private jets are an extremely affluent and extremely small market.
First impression is everything with this group of folks who put huge value on their time (they are willing to spend millions on a private jet to save themselves hours of travel).
These consumers don't just interface with the World's top brands, in many cases they own/run those companies.
Trust, credibility, and professionalism are the most important elements that need to be conveyed through the logo for this new brand.
While I am not convinced that this will be possible (and may be a red-herring), I would be thrilled if you could come up with a graphic element (that's not cartoon-like) that conveys both that the brand is about private jets and that it's about buying/selling.
The overall logo needs to work for the web, business cards, and golf/polo shirts.