Ending a sentence with "is it" is really common in Hiberno-English, i.e. the particular form of English spoken in Ireland. People often use it as a sort of confirmation of what they're talking about - rather than asking for someone else to confirm, they're sort of doing it themselves, as it were... You meet someone, they tell you your name, you say, "It's Kate, is it?" and so on. Or you might say, "it's a sandwich you'd like, is it?"
No, if you feel the need to equate ann with "there", then "there is a sandwich" would be a better translation ("there is" as in "there is a God" rather than "over there/in that place). It is the "ann of existence", not the "ann of position".
And if you are being literal, an ea? is "is it?", and nach ea? is "isn't it?"