I personally love Etta. It reminds me of Etta James, a really lady in her time. However, I don't care for Etta Susannah.... it's got an -a -a thing going. Plus, I feel like Etta needs a really vivacious, feminine name to spice it up.
Susannah is a name that i definitely wanted to use, partly because i love it and it also honours a dear great aunt of mine. Etta is a new crush, and i was hoping they could work together. However, from your list, Etta Rosalie leaps off the page at me-i love it! Not sure where that leaves Susannah though... :-)