I like
Sorcha "SORE-sha". I don't think there's anything wrong with using the Anlicized pronounciation, it's prettier to me than "SUR-ka" or "SOR-ka" (these make me think of circa, like circa 19th century). I do think most people will say "SORE-cha" on the first try but it's an easy correction. A friend of mine is named
Charla "
Sharla" and it's always a quick fix when people say it wrong the first time. And I think it goes wonderfully with
Ronan!
Unfortunately I'm not a huge fan of any of your middle names but
Sorcha Helena is the one I would choose if I had to.
Sorcha Aurora For- definitely has too many "or" sounds in it.