I like both Mirna and Myrna but they're pronounced differently. The former is "meer-na" and the latter is "mur-na". Mirna has a softer sound.
From your list, I like the following combos:
Mirna Rosalind
Mirna Cecily
Mirna Juliet
Mirna Celeste
Mirna Solveig
Mirna Isobel
Mirna Cecile