What about Sigillum Sanguis? I'm not even going to try. I say it like sang - guis (as in kiss).
Is there a correct pronunciation for this?
That would be correct. It's a conjugation of sanguine (the latin word, not the daedra). San-gween becomes San-gwiss.
Although, I do rather enjoy calling it the Sigillum Sammich, as in baloney sammich.