WWW,
If I were this chap to whom you are referring, I would consider NetJets (i.e., Executive Jet Aviation) first and Flexjet second. Note that NetJets is ramping up its operation in Europe and adding Falcon 2000s (they have a total of 60 on order for its operations in the US, Europe and Middle East) and Hawker 800XPs. I believe the total Falcons on order for Europe is expected to be 24 (not certain) with a few already operating. I think Netjets already operates Citation VIIs and IIs in the European region with plans to upgrade very soon.
Also, NetJets is extremely successful in the US and is owned by the second richest American - Warren Buffet - he's worth $20 billion. He is very committed to making the operation work in Europe. It is also conceivable that BBJs might join the European fleet eventually - 24 are on order for the US fleet.
Flexjet would also be a great choice. I believe it is ramping up on Challenger 604s and Lear 60s - both very nice.
You win in either case. Best of luck to you!
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In the land of the blind, the one-eyed pilot is king!