"strong willing" is correct and usable in written English.
It is an adjective phrase which can be used to describe a person who is determined and resolute in achieving a goal. For example, "The team was made up of strong willing athletes determined to win the championship".
Quick, strong, willing... and usually some distance from team-mates.
At a time when Republicans want to paint Mr Obama as a ditherer, unwilling to take firm action, it paints him as tough and strong, willing to take hard decisions and kill America's enemies.
This woman is selfless, loving, strong, willing, and able all balled into one.
But what I will promise her is that I will listen to her, I will hear her, I will help her to make peace with her previous experience, I will support her and I will do all that is possible to prepare her, so that when her time comes to birth, she'll be going into it with a clear head, free from the past birth experience, strong, willing, able and ready to birth again.
Country girls are bubbly, bright, strong-willing, funny, and down-to-earth people.
Ms. Mink was known as articulate and strong-willed, and willing to fight for causes large and small.
Or maybe we just need one smart and strong-willed mom willing to bridge the divide, a mom mediator of sorts.
"A BBC that puts forward a bold proposal for Scotland, for the nations and regions, and for the UK will have in us a strong and willing ally.
Where the strong are willing to use violence to thwart the popular will, democratic movements can be stopped in their tracks, as in Myanmar, or provoked into a violent reaction of their own, as in Kenya.
"This is a big job in Boston, as it is in New York, and I think we need someone who's confident and strong and willing to make arguments.
Martha Holstein Chicago, Aug.21, 2009 To the Editor: Difficult times require strong leaders willing to act with courage and conviction — in short, to lead.
