1+ to this.

You mentioned mostly wanting to go lower *in the drops* yes?

As the Nomad notes, both pictured bikes have seemingly quite shallow drop bars. Try a Cinelli Campione del Mondo, a Deda 215 Deep, or something similar...and you will have your solution, but without going to a track stem (which might or might not be an aesthetically pleasing option to you). I'm personally inclined to keep the extension on a quill stem relatively level with the TT, where possible - but that's definitely in the realm of personal preference!

If you're perfectly happy with where your tops/hoods are at with the existing quill slammed, but want deeper drops, a bar swap is certainly worth a try.

If the whole assembly needs to move down: track stem, FTW.