Have you looked at the Tiffany Embrace? It's a single halo ring, and in the 1.6 -1.8 carat range it would be AMAZING. Mine is only .82, but seriously looks so much bigger, and it sparkles like crazy! I get complements on it just about every day. I'm attaching photos, but they're both from a camera phone, so they don't come anywhere close to showing off how amazing it is!
Good luck on your search!!
ooh so pretty! I just helped my little brother buy this for his fiance and it's a gorgeous option - huge coverage and so pretty!!! Like you said sparkles like no tomorrow - I love it!