She LOVES this setting (the baguette with the platinum, squared band), yet I can't find any online site that has anything like it. Can someone point me in the right direction or should I take the picture to a local jeweler?
Those are tapered baguettes and double prongs on the ring that you posted, OP. Aside from the double prongs, which are more of a recent trend, that is a classic setting for an emerald cut or square cut. Harry Winston might have been the origin of it. Probably Adwar and Unique Settings of NY and other major casting houses have something similar. If the mounting has thick single prongs, sometimes a bench jeweler can split them and turn it into double claws. But that's not a given. The single squarish prong at each corner is classic.
You could try working with someone that does custom work? Whiteflash, Victor Canera, Brian Gavin all come to mind... Just get in touch with them and send them that picture. They can probably help you source out the diamonds as well. Just a thought
I had a similar ring made - yes it's the tapered baguette setting. If you are going to go the custom route, I can recommend Steven Kirsch, who made mine (chains below). Leon Mege and Victor Canera also make these styles, although I haven't had anything made by them (although their work is beautiful, as you can see here on PS).
(Make sure you scroll past the first photo which is of a previous ring.)
This ring is basically the same as yours, but with less elongated sides (trapezoids rather than your tapered baguettes). The setting was done by Victor Canera, and the side stones are set without inside prongs (using a 'groove set' system), which REALLY cuts down all the excess metal, making it look lighter, more delicate and more blingy. I'm sure he would do the setting you're looking for - which is basically the same but with tapered baguettes. Definitely worth a call.
You can also get CAD/cast instead of hand-forged work from ERD, based on your budget. ERD can quote both ways.
For hand forged, I agree that Victor Canera and Steven Kirsch are good choices. VC is located in CA, and SK is in NYC. You may want to choose based on your location.