Round Core Bass Boomers had the balanced construction a little while back. You have to order them as singles to get the 45-60-80-105 or 40-55-75-100 balanced sets, but that's an option. Even if you get the packaged sets, they're more balanced than a typical 45-105 set would be.
The Pressurewound Bronze are also created in this way too. They work on an electric bass, but you'll need to tweak some settings as they're quieter than other, more ferrous sets.
The roundcore bass boomers no longer have the balanced construction?