For what NetJets Europe flies, see
here. The fleets that have FAs start at the Hawker 4000. The taller folks have no problem on the Falcon and bigger but I can't recall the height of the cabin for the Hawker 4000. (It's not in service with us yet)
NetJets after Ryanair? Nothing's impossible but you might have to get another language or more importantly, prove you have VVIP skills and awareness.
If you've done silver service or catering previously then that will be viewed highly.
Hire men? Yes, they have done so in the past. No idea what the current policy is now. Obviously, a language or two never goes astray. French or Russian are particularly useful. You'll need to show that you can work independantly and work with the pilots.
Good luck.