I don't visit this area of the forum much and I see your post has been on here since September with no replies. The practical considerations you describe seem to be tremendous hurdles. I'm afraid you can't follow your heart on this one.
First, you say he's still married. Strike number one. Second, he has huge financial debt. Strike number two. Third, he lives far away.
If he leaves his wife for you, how do you know he won't leave you for another heartthrob somewhere down the road.
Financial debt puts a huge strain on even good relationships with a solid foundation.
Third, the distance obstacle really makes this an impossible dream. You might just be a safe dalliance for him. Someone to flirt with on the side who is safe because he knows how high the other hurdles are.
Sorry, but that's the opinion of a 55 year old man. If you try I'm sure you can find a good man, relatively debt free and single closer to home. You may be infatuated with him because for these three reasons, he is "forbidden fruit". If you were my daughter (I have one who is 35 and divorced) I'd say the same thing. Forget about him.