I have this OXO Good Grips 11-Inch Balloon Whisk (eG-friendly Amazon.com link). It's 11 inches overall and the wire part is ~ 6.5 inches long. Not sure that suits your size needs but the wires are sealed in the way you describe. They make other sizes, not sure if the design is the same.
Here's a photo, where I hope you can see the way the wires are surrounded by a clear sealing material:
Ooops. I just realized that you said all-stainless and this one has a plastic handle. Sorry!