I think the problem here is that channel set was big in the '80s/'90s yellow gold era and that predates Pricescope. I'll try to dig up some of the more unusual stuff. I really like that WF legato, though.
With either of these styles, you'd need a custom wedding band or would need to buy the matching band from the manufacturer, if there is a matching band, because you'd need a shaped band shaped to hug the e-ring setting. From a seller on etsy, there's a bypass ring. http://www.etsy.com/listing/64151416/moissanite-engagement-bypass-ring-with
Sholdt does something similar, #R4591D. Other companies do similar.
Sholdt also has the half-bezel #R4177D
If you like the more contemporary rings, you can take a look at Knox Diamonds. But you'd have to buy the center diamond from them. They've never been a PS vendor.
These are some vintage ones from my photo collection. Some of those '80s styles would look rather contemporary in white gold, palladium, or platinum. Or perhaps rose gold, but it would be more trendy.
There is a Whiteflash custom setting someplace 'way back in SMTB that I always liked. I think it's channel set but it would me take a long time to find it.
Last "vintage" pic I have. Most of the channel set settings I have seen online are some variant of a prong head + a narrow shank with channel set diamonds in it.
What do you all think of this one. It's just over a 2 mm band (like 2.2). I know that she wants a dainty band that's not chunky or overwhelming. I'm hoping this is right up her alley. She's a nurse, so that's especially why I'm looking for a channel set ring because I don't want it to bug her and get caught in things all day. And yes, she's allowed to wear the ring to work. I especially like the surprise diamond. I think it adds just the right amount of uniqueness to the setting. I also like the little swoop thing underneath the mounting! That's what I'd call it anyway
Around a 1.15 or 1.2 carat will be the center stone.