First of all, congratulations.
My own experience was wonderful. I found a local goldsmith who custom made a ring. It's a white gold Celtic knotwork design with a somewhat heavy
bezel setting for the diamond (which suits her). It looks solid rather than dainty, which is what we wanted. That's the thing, you can tell the guy making it what you want. Plus, depending on the operation (this one is small: him and his wife), it will be a bucket of cash cheaper.
If you want to go this route, take her with you to have a look at the designs. I guess it would be kinda like getting a tattoo. You talk to the artist, have a look at their portfolio, and then tell them what you want.
Here's where I got the ring. Have a look and see if you have a similar place locally:
The Claddagh House