If my vote isn't too late, I say keep it if money isn't an issue.
You have already in short said the car is near and dear to you. If that is the case you will in short time regret selling it.
I believe these cars are special too. BMW has never before put an NA V8 in the M3 and never will again. It was a one and done move by BMW. They saw the writing on the wall with turbos and said lets do this while we can.
I'm sure you will find another when you decide you want one again however for the reasons you stated in your post it won't be the same.
KEEP IT
