You could always contact Mr. Sadowsky (
www.sadowsky.com). He has two different gauges available for both 4 string and 5 string, as well as an XL set for 5 string.
I think they give you what you are looking for in a typical flatwound, with a little more clarity on the low end. They are also very nicely finished.
La Bella tape wounds would move you even further to mellow. I am a big fan of them.