My favorite bars right now are the Velo Orange Crazy Bars (V2) I find those to be super comfortable but also have a lovely position when I need to stretch out a little. However if you want a more traditional flat bar there are tons of options and your local shop is likely to have it.

Proprietary Trek Garbage is the worst followed by all the other proprietary garbage out there. A handlebar and a dropouts are not a place you need mess around and try and create something new just stick with a standard clamp and diameter and either QR or Thru-axle in the standard sizes we have had for a while. If you want to make improvements make improvements but don't push proprietary crap-o-la on people who might not know any better.