Butterfly trekking bars will either extend or shorten your reach to the controls (depending how you set them up, using your current stem).

Dirtdrop type bars can allow you to have controls at the same reach you have with a flatbar (but possibly a bit narrower/closer together), and give you the hood position that would be comparable to long bar ends (only with access to brakes), and give you a wide drop position.

But it may necessitate replacing shifters depending on what you're starting with and what positions you want.

You could combine mtb brake+shifter units with non-aero road brake levers, but cable routing would be a nightmare. Using aero road brake levers with cross brakes should work fine, but if your shifters are integrated with brakes that creates a problem. Some of Shimano's combined units used a single bolt mount that was the same on some of their stand-alone shifter pods, but I don't think they sold just the mount clamp so getting the part to make the integrated shifters stand alone would probably be more trouble then it's worth.