iPhone 6 on Virgin Mobile?

I spoke with a rep at Virgin Mobile today. I have an account at Virgin Mobile and want to update the phone to an iPhone 6. The Virgin Mobile rep told me I could buy an unlocked iPhone 6 that is "compatible with Virgin Mobile" from Apple and then get it activated at Virgin Mobile. I then spoke with an Apple rep to purchase a "Virgin Mobile compatible" unlocked iPhone 6. He expressed some concerns about compatibility with Virgin Mobile based on what he was reading on the Virgin Mobile website.

Does anyone know for sure whether an unlocked iPhone 6 can be used with Virgin Mobile? Thanks in advance.