Jayna & Janae are both on my list! I think I am deffinetely going to use Janae someday because it's a great alternative to Renae which goes well with many FNs. I think both names are cute! :-)
It might be like a lot of Greek names that are widely pronounced in strange ways because people make a guess. DAN-ay-ee is definitely correct. DUH-nay would be the equivelant of pronouncing Zoe "zoh".
I really don't like JaynaDanae or Jayna Luray. JaynaJanae is not only too sing songy, but come from the same name so I wouldn't use that. The other combos are just nmsaa.
Jayna and Janae are both modern variations of Jane, so JaynaJanae is a bit redundant. Jayna is nms, but I like Danae (it's pronounced dan-ay-ee, btw, not like Janae which is jan-ay).