There are a number of conventional posts with more setback than Thomson offers, probably up to 1/2-3/4" more depending on the post. Unfortunately setback isn't a spec covered accuately in many poduct details, so you'll have to find and measure a few. (or get volunteers to measure theirs and report back).

If you need more than that, there used to be some posts made with extended or adjustable setback like this one. From time to time the concept is reintroduced, so you can probably find something if you look around.

BTW- the photo I linked is from Yellow Jersey in Wisconsin. They'd be a good place to start the search once you know the diameter needed.