I'm having the same dilemma! I have a three-stone trellis setting, and I don't really think a plain band looks right with the intricacy of the trellis setting. I had my heart set on a trellis setting, but i never told my fiance, and low and behold he designs a three-stone ring with a trellis setting! It is a diamond centre stone with pink sapphires on each side, so I also have the trouble of matching something with the pink (but I LOVE it).
I have been looking at "shared setting" rings with diamonds and sapphires. We're going to have the jewelry designers that my fiance had make my ring do the bands, but I found the pictures at Tiffany's. Tiffany's is WAY too expensive for us, but luckily we know this designer who can make us the ring for basically cost + labour.
I'm sure once you know to search for "shared setting" you may be able to find similar rings at another jewelry store or online.
Pictures:
Shared setting diamonds:
http://www.tiffany.ca/Shopping/Item.aspx…
Shared setting for me:
http://www.tiffany.ca/Shopping/Item.aspx…
Mine doesn't go all the way around for comfort and cost reasons.