I’ve mentioned it a fair few time in various threads and feel I must point out I have no affiliations with Planet X or anything in the biking world. 😉
Their Whippet frame is IMO exactly what your looking for. I made similar references to the ride characteristics when I had it.
However, when I’d finished with it, the build was very close to my main HT, a SC Carbon Chameleon, so that could also be looked at too. The latest one has slightly different geometry so perhaps one from a few years ago may be more suitable.
Other than that, I’d scope out something with similar geometry to the Whippet if you fancy a better name etc.