Backwoodsman, as I said, to me singing in ones own voice is important, but for you it isn't.
It's a pity though, because you would be far more interesting - without any doubt - as a singer, if you sang you're R&B material in you natural voice! Why? Because, apart from anything esle, you would stand out from the crowd as a true individual rather than one of tens of thousands of Brits who adopt silly American accents.