Hi:
While catalogs are notoriously inexact in assigning a species or hybrid name to various ipomoea cultivars (such as these), the consensus appears to be that they are all Ximperialis or at least in the same subgenus and section of ipomoea. So, crosses should be possible. There will likely be some variation even with the selfings, and even more if cross hybridization occurs.
mike

I believe the three varieties you mentioned are stable inbreds and will breed true if selfed. If allowed to cross...surprise!

I had them growing all together along a fence and saved some seeds from them. I can't wait to see what kind of variations I get!

What happened with them? How did they turn out?