Congrats, its so much fun! I am glad to found the right one for you, I know it seems silly- but it can be a real challenge.
I am right now going around looking, and looking, and looking! Like wedding dresses, "they all look the same" and it is hard to find something that feels "you" and significant. We are not in any hurry, but seeing as we are on this topic, I want to bring this up for any other couples out there!
I really favour antique rings as well, just it feels nice to know that one has something with charactor (and hopefully good history) and that we are not adding to unneccessary distruction of the earth for mining or pain, suffering, slavery and war.
I am aware of the Kimberley process, but, I must say- I don't entirely trust it. That, and just tearing apart the earth for metals/stones does bother me. Most of us have inherited pieces we don't wear and won't ever- so what I am opting to do is just keep a few originals that have stories I love to pass on, and reuse the other things.
So, with that in mind, here are a few favourite sites:
www.greencarat.com
www.krikawa.com
www.moissaniteco.com
Personally, I love the idea of his/her matching set. He loves the mokume, I like the idea of remanufactured metal and we both love the idea of moissanite. Tee Hee- for way less money, we can have totally "us" rings and HUGE honking sparklies! Apparently, many jewelers even think they are diamond, and they wear better. Benefit to me, my birds are always chewing on my rings.
hahaha!
Enjoy!

J