weeper, I am not sure where to find these.... but then I must tell you that the two maples that I planted last summer did very well over the winter, with zero winter die back and have leafed out beautifully! Their names are:

1. Prairie Splendor Maple

2. Royal Red Norway Maple

Both have dark red leaves and are lovely. So far, the Royal Red Norway Maple leafed out later, but is taller but less dense, while the Prairie Splendor Maple is much denser but shorter. I love their dark foliage. I wonder if these would work for you?